opinion: Mr. Justice Stewart
  delivered the opinion of the Court.
  The 1970 election for the office of United States Senator was the closest in Indiana history. The incumbent, Senator R. Vance Hartke (Hartke), was declared the winner by a plurality of 4,383 votes — a margin of approximately one vote per state precinct. On November 16, 1970, 13 days after the election, the Indiana Secretary of State certified to the Governor that Hartke had been re-elected. On the following day, candidate Richard L. Roudebush (Roudebush) filed in the Superior Court of Marion County a timely petition for a recount. Hartke moved in that court to dismiss the petition, arguing that the state recount procedure conflicted with the Indiana and Federal Constitutions. On December 1, the state court denied the motion to dismiss and granted the petition for a recount. It appointed a three-man recount commission and directed it to begin its task on December 8.
  Hartke then filed a complaint in the United States District Court for the Southern District of Indiana asking for an injunction against the recount. He invoked federal jurisdiction under 28 U. S. C. § 1343 (3) and claimed that the recount was prohibited by Art. I, § 5, of the Constitution of the United States, which delegates to the Senate the power to judge the elections, returns, and qualifications of its members. A single district judge issued an order temporarily restraining the recount pending decision by a three-judge district court. The Attorney General of Indiana then moved successfully to intervene as a defendant, and a three-judge court was convened pursuant to 28 U. S. C. § 2284. After taking testimony and hearing argument, the court ruled in Hartke’s favor and issued an interlocutory injunction, 321 F. Supp. 1370, one judge dissenting. Roudebush and the Attorney General both brought direct appeals to this Court.
  On January 21, 1971, shortly after the jurisdictional statements were filed, the Senate administered the oath of office to Hartke, who had been issued a certificate of election by the Governor. Hartke was seated, however, “without prejudice to the outcome of an appeal pending in the Supreme Court of the United States, and without prejudice to the outcome of any recount that the Supreme Court might order . ...” Following the Senate’s decision to seat him, Hartke moved to dismiss the appeals as moot. We consolidated both appeals and postponed further consideration of questions of jurisdiction to the hearing of the cause on the merits. 401 U. S. 972.
  I
  We consider first the claim that these appeals are moot. This claim is based upon the proposition, as stated in appellee Hartke’s brief, that the “basic issue” before the Court is “whether appellee Hartke or appellant Roude-bush is entitled to the office of United States Senator from Indiana.” Since the Senate has now seated Hartke, and since this Court is without power to alter the Senate’s judgment, it follows, the argument goes, that the cause is moot.
  The difficulty with this argument is that it is based on an erroneous statement of the “basic issue.” Which candidate is entitled to be seated in the Senate is, to be sure, a non justiciable political question — a question that would not have been the business of this Court even before the Senate acted. The actual question before us, however, is a different one. It is whether an Indiana recount of the votes in the 1970 election is a valid exercise of the State’s power, under Art. I, § 4, to prescribe the times, places, and manner of holding elections, or is a forbidden infringement upon the Senate’s power under Art. I, § 5.
  That question is not moot, because the Senate has postponed making a final determination of who is entitled to the office of Senator, pending the outcome of this lawsuit. Once this case is resolved and the Senate is assured that it has received the final Indiana tally, the Senate will be free to make an unconditional and final judgment under Art. I, § 5. Until that judgment is made, this controversy remains alive, and we are obliged to consider it.
  II
  It is the position of the appellants that, quite apart from the merits of the controversy, the three-judge District Court was barred from issuing an injunction by reason of 28 U. S. C. § 2283, which prohibits a federal court from enjoining state court proceedings except in a few specific instances. This argument has weight, of course, only if the Indiana statutory recount procedure is a “proceeding in a State court” within the meaning of § 2283. This Court has said of a predecessor to § 2283, “The provision expresses on its face the duty of ‘hands off’ by the federal courts in the use of the injunction to stay litigation in a state court.” More recently, we characterized the statute as designed to assure “the maintenance of state judicial systems for the decision of legal controversies.”
  We have in the past recognized that not every state court function involves “litigation” or “legal controversies.” In the case of Prentis v. Atlantic Coast Line R. Co., 211 U. S. 210, the Court reviewed a federal injunction preventing a state commission from fixing passenger rail rates. The Court assumed that the commission had the powers of a state court and that the predecessor of § 2283 governed any attempt by a federal court to enjoin the exercise of the commission’s judicial powers. Nevertheless, the Court concluded that rate-making could be enjoined because it was legislative in nature. Hence, the Court held that § 2283 does not restrict a federal court from enjoining a state court when it is involved in a nonjudicial function.
  To determine whether an Indiana court engages in a judicial function in connection with an election recount, we turn to the law of that State. In Indiana every candidate has a right to a recount and can obtain one by merely filing a timely petition in the circuit or superior court of the appropriate county. If the petition is correct as to form, the state court “shall . . . grant such petition . . . and order the recount . . . .” When it grants a petition, the court is required to appoint three commissioners to carry out the recount. Once these appointments are made, the Indiana court has no other responsibilities or powers.
  The exercise of these limited responsibilities does not constitute a court proceeding under § 2283 within the test of Prentis: “A judicial inquiry investigates, declares and enforces liabilities as they stand on present or past facts and under laws supposed already to exist. That is its purpose and end.” 211 U. S., at 226. The state courts’ duties in connection with a recount may be characterized as ministerial, or perhaps administrative, but they clearly do not fall within this definition of a “judicial inquiry.” The process of determining that the recount petition is correct as to form — that it contains the proper information, such as the names and addresses of all candidates, and is timely filed — is clearly not a judicial proceeding. Nonjudicial functionaries continually make similar determinations in the processing of all kinds of applications.
  And finally, Hartke’s complaint in this cause did not ask the three-judge federal court to restrain the action of the Indiana court as such. It did not seek to enjoin the state court from ruling on the formal correctness of the petition; it did not even seek to enjoin the state court’s appointive function. It sought, rather, to enjoin the recount commission from proceeding after the court had appointed the members of the commission.
  We conclude that the three-judge District Court was not prohibited by § 2283 from issuing and had power under 28 U. S. C. § 2281 to issue, an injunction in this cause.
  Ill
  We turn, therefore, to the merits of the District Court’s decision. The Indiana Election Code calls for the vote to be initially counted, in each precinct, by an election board. After recording the voting machine totals, the board seals the machines. Paper ballots, including absentee ballots, are then counted and tallied. Counted ballots are placed in a bag and sealed. Ballots that bear distinguishing marks or are mutilated or do not clearly reveal the voter’s choice are not counted. These rejected ballots are sealed in a separate bag. Both bags are preserved for six months and may not be opened except in the case of a recount.
  If a recount is conducted in any county, the voting machine tallies are checked and the sealed bags containing the paper ballots are opened. The recount commission may make new and independent determinations as to which ballots shall be counted. In other words, it may reject ballots initially counted and count ballots initially rejected. Disputes within the commission are settled by a majority vote. When the commission finishes its task it seals the ballots it counted in one bag, and the ballots it rejected in another. Once the recount is completed, all previous returns are superseded.
  The District Court held these procedures to be contrary to the Constitution in two ways. First, the court found that in making judgments as to which ballots to count, the recount commission would be judging the qualifications of a member of the Senate. It held this would be a usurpation of a power that only the Senate could exercise. Second, it found that the Indiana ballots and other election paraphernalia would be essential evidence that the Senate might need to consider in judging Hartke’s qualifications. The court feared that the recount might endanger the integrity of those materials and increase the hazard of their accidental destruction. Thus, the court held that, even if the commission would not be usurping the Senate’s exclusive power, it would be hindering the Senate’s exercise of that power.
  We cannot agree with the District Court on either ground. Unless Congress acts, Art. I, § 4, empowers the States to regulate the conduct of senatorial elections. This Court has recognized the breadth of those powers: “It cannot be doubted that these comprehensive words embrace authority to provide a complete code for congressional elections, not only as to times and places, but in relation to notices, registration, supervision of voting, protection of voters, prevention of fraud and corrupt practices, counting of votes, duties of inspectors and canvassers, and making and publication of election returns; in short, to enact the numerous requirements as to procedure and safeguards which experience shows are necessary in order to enforce the fundamental right involved.” Smiley v. Holm, 285 U. S. 355, 366.
  Indiana has found, along with many other States, that one procedure necessary to guard against irregularity and error in the tabulation of votes is the availability of a recount. Despite the fact that a certificate of election may be issued to the leading candidate within 30 days after the election, the results are not final if a candidate’s option to compel a recount is exercised. A recount is an integral part of the Indiana electoral process and is within the ambit of the broad powers delegated to the States by Art. I, § 4.
  It is true that a State’s verification of the accuracy of election results pursuant to its Art. I, § 4, powers is not totally separable from the Senate’s power to judge elections and returns. But a recount can be said to “usurp” the Senate’s function only if it frustrates the Senate’s ability to make an independent final judgment. A recount does not prevent the Senate from independently evaluating the election any more than the initial count does. The Senate is free to accept or reject the apparent winner in either count, and, if it chooses, to conduct its own recount.
  It would be no more than speculation to assume that the Indiana recount procedure would impair such an independent evaluation by the Senate. The District Court’s holding was based on a finding that a recount would increase the probability of election fraud and accidental destruction of ballots. But there is no reason to suppose that a court-appointed recount commission would be less honest or conscientious in the performance of its duties than the precinct election boards that initially counted the ballots.
  For the reasons expressed, we conclude that Art. I, § 5, of the Constitution, does not prohibit Indiana from conducting a recount of the 1970 election ballots for United States Senator. Accordingly, the judgment of the District Court is reversed.
  It is so ordered.
  Mr. Justice Powell and Mr. Justice Rehnquist took no part in the consideration or decision of these cases.
  Roudebush filed similar petitions in 10 other counties. Recounts in all 11 counties have been postponed, pending the outcome of this cause.
  Title 28 U. S. C. § 1343 provides:
  “The district courts shall have original jurisdiction of any civil action authorized by law to be commenced by any person:
  “(3) To redress the deprivation, under color of any State law, statute, ordinance, regulation, custom or usage, of any right, privilege or immunity secured by the Constitution of the United States or by any Act of Congress providing for equal rights of citizens or of all persons within the jurisdiction of the United States.”
  The District Court apparently viewed the suit as substantively based upon 42 U. S. C. § 1983, which authorizes a civil action on the part of a person deprived, under color of state law, “of any rights, privileges, or immunities secured by the Constitution . . .
  U. S. Const., Art. I, § 5, provides in pertinent part:
  “Each House shall be the Judge of the Elections, Returns and Qualifications of its own Members . . . .”
  Direct appeals from such interlocutory orders are authorized by 28 U. S. C. § 1253.
  117 Cong. Rec. 6.
  See Reed v. County Comm’rs, 277 U. S. 376, 388: “[The Senate] is the judge of the elections, returns and qualifications of its members. Art. I, § 5. It is fully empowered, and may determine such matters without the aid of the House of Representatives or the Executive or Judicial Department.”
  Powell v. McCormack, 395 U. S. 486.
  U. S. Const., Art. I, §4, provides in pertinent part:
  “The Times, Places and Manner of holding Elections for Senators and Representatives, shall be prescribed in each State by the Legislature thereof; but the Congress may at any time by Law make or alter such Regulations, except as to the Places of chusing Senators.”
  See Powell v. McCormack, supra, at 496.
  Title 28 U. S. C. §2283 provides:
  “A court of the United States may not grant an injunction to stay proceedings in a State court except as expressly authorized by Act of Congress, or where necessary in aid of its jurisdiction, or to protect or effectuate its judgments.”
  The statute dates from 1793. Act of Mar. 2, 1793, § 5, 1 Stat. 334.
  Toucey v. New York Life Ins. Co., 314 U. S. 118, 132. (Emphasis supplied.)
  Atlantic Coast Line R. Co. v. Brotherhood of Locomotive Engineers, 398 U. S. 281, 285. (Emphasis supplied.)
  See Hill v. Martin, 296 U. S. 393, 398.
  Ind. Ann. Stat. §§ 29-5401 through 29-5417. The election recount provisions of some other States appear to give the state courts a broader function. See, e. g., Conn. Gen. Stat. Rev. § 9-323 ; Va. Code Ann. §24-277.1 (1969).
  The role of the Indiana courts in this connection is not unlike that of the state court in the case of Public Service Co. of Northern Illinois v. Corboy, 250 U. S. 153. A state statute there authorized property owners to petition a state court to establish a drainage district and to construct a drainage ditch. To assist in the planning of a ditch, the state court was empowered to appoint a drainage commissioner. The commissioner served on a commission that submitted plans for construction. The state court could either accept or reject these submissions. If it approved plans, the court allocated funds and supervised construction. Applying Prentis, this Court held that these activities were not judicial, and that enjoining the construction of a drainage ditch was not enjoining a state court “proceeding.” See also Central Electric & Gas Co. v. City of Stromsburg, 192 F. Supp. 280, aff’d, 289 F. 2d 217 (federal court could enjoin a state court’s appointment of an appraiser pursuant to a state statute); Central R. Co. of New Jersey v. Martin, 19 F. Supp. 82, aff’d sub nom. Lehigh Valley R. Co. v. Martin, 100 F. 2d 139 (federal court could enjoin ministerial act of state judge, pursuant to state statute, converting a state tax into a lien against the taxpayer) ; Weil v. Calhoun, 25 F. 865 (federal court could enjoin a state ordinary, having the powers of a probate judge, from declaring the results of a county election).
  The only injunctive relief sought in Hartke’s amended complaint was “that the court permanently restrain and enjoin the defendants and restraining and enjoining the defendants Samuel Walker, John R. Hammond and Duge Butler [the recount commissioners) from convening and commencing a recount, and the defendant Richard L. Roudebush and all persons acting in his behalf or in concert with him [from] taking any further action to use said machinery and procedures to carry forward a recount of the vote for the office of United States Senator in the general election of November 3, 1970.” An interlocutory injunction against- the same defendants was also sought.
  Ind. Ann. Stat. §§ 29-5201 through 29-5220.
  Ind. Ann. Stat. §§ 29-5401 through 29-5417.
  The District Court cited three cases decided by the Indiana Supreme Court as authority for its rulings. State ex rel. Batchelet v. Dekalb Circuit Court, 248 Ind. 481, 229 N. E. 2d 798; State ex rel. Beaman v. Circuit Court of Pike County, 229 Ind. 190, 96 N. E. 2d 671; State ex rel. Acker v. Reeves, 229 Ind. 126, 95 N. E. 2d 838. These cases held that the Indiana Constitution prohibited recounts in certain state elections. They do not address the federal constitutional question at issue in this cause.
  See n. 8, supra.
  The Secretary of State is required by statute to certify to the Governor the leading candidate as duly elected “as soon as he shall receive” certified statements from the counties. The statutory period for receiving those statements is 26 days. The Governor is required to give a certificate of election to each certified candidate. Ind. Ann. Stat. §§29-5306 through 29-5309.
  A petition for a recount may be filed 15 days after the election is held. §29-5403. The petition cannot be granted nor the recount commission appointed by the court for another 25 days. § 29-5409. The recount may not commence until at least five days after the commission is appointed. §29-5411. Additional time elapses before the results are made final and the appropriate persons are notified. Thus, the recount is unlikely to be completed before the Governor becomes obligated by statute to issue a certificate of election based on the initial count. Nevertheless, the recount supersedes the initial count even though a certificate of election may have been issued. § 29-5415.
  The Senate’s power to judge the qualifications of its members is limited to the qualifications expressly set forth in the Constitution. Powell v. McCormack, 395 U. S. 486. One of those qualifications is that a Senator be elected by the people of his State. U. S. Const., Amend. XVII.
  The Senate itself has recounted the votes in close elections in States where there was no recount procedure. E. g., O’Conor v. Markey, Senate Election, Expulsion and Censure Cases from 1789 to 1960, S. Doe. No. 71, 87th Cong., 2d Sess., 144 (1962).