Id. at 404. To support a § 841(b)(1)(B) statutory enhancement, the government must file an information notifying the defendant of the enhancement and the prior convictions upon which it is based. 21 U.S.C. § 851(a)(1). The defendant may respond that the conviction was obtained in violation of the U.S. Constitution, and bears the burden of proving the conviction’s constitutional infirmity by a preponderance of the evidence. Id. § 851(c)(2). However, he may not “challenge the validity of any prior conviction alleged under this section which occurred more than five years before the date of the information alleging such prior conviction.” Id. § 851(e). We have upheld the validity of § 851(e)’s limitations period. See United States v. Williams, 954 F.2d 668, 673 (11th Cir.1992) (<HOLDING>). The specific subsection of the Florida drug
recognizing that reasonable time limitations may be placed on the exercise of constitutional rights holding that although court should inform jury about defendants prior sentences the court should instruct the jury that it should not consider prior sentences in its decision to impose a life or death sentence because they are not statutory aggravating or mitigating factors holding that imposition of lengthy sentences did not show prejudice where sentences were warranted by facts shown in the evidence holding that  851es limitations period was constitutional because it was reasonably tailored to impose enhanced sentences on recidivists holding that the federal constitutional right to a jury trial does not apply to decisions to impose consecutive sentences