Argument: The need to constantly fight elections compromises a politician's ability to make the difficult and unpopular decisions that may be needed at a given time:

A major focus of a legislator hoping to serve another term is on the next election and on vote getting. It is often the case that hard decisions need to be made by legislators, but it is difficult for them to do so when they are fixated on being reelected. Legislators have an incentive to put tough decisions off if they can retain power by doing so. An example of such seemingly perpetual procrastination is observable in the United States Congress's attitude toward social security. The fund is set to become insolvent, by some estimates, in less than two decades, yet congressmen and senators have chosen time and again to put off enacting painful, but necessary reform to the system. They find it easier to delay a decision until the next Congress, preferring their own reelection to the good of the nation. When constrained by term limits, legislators must make the most of their limited time in office, resulting in greater prioritization of difficult decisions and reform1. Furthermore, the need to constantly fight elections places politicians in the pocket of lobby-groups and election supporters to a greater degree, as they will always need to go back to them for support, and thus cannot make decisions that are in the national interest alone. While there will always be some of this behavior, it is curtailed by term limits, as legislators will, in their final term at the very least, not be beholden to as many special interests as they cannot run again. Bolder legislative action is observed from retiring legislators in the United States Congress, for example. When a congressman or senator does not intend to seek reelection, his tendency to vote along strict party lines diminishes substantially. Term limits, just like voluntary retirement, leads legislators to vote more on the basis of principle than on party stance2. The result of this is a more independent legislature, with a greater interest in actually serving the people.

1 Chan, Sewell. 2008. "Debating the Pros and Cons of Term Limits". New York Times. 2 Scherer, Michael. 2010. "Washington's Time for Bipartisanship: Retirement". Time.

Candidate 1: "People are intelligent enough to recognize whether a representative is benefiting them or not. They will not vote for someone who is using his privileged position in the legislature to enrich himself or build a fiefdom of influence. Rather, legislators will only be able to stay in office so long as they do what their constituents want. If legislators are maintaining their power by other means, such as institutionalized corruption and force, it is not because there are no term limits on them, but rather because of other fundamental problems of government in those states."
Candidate 2: "A politician who has to constantly concern himself with reelection has a much greater likelihood of being beholden to special interest groups and lobbyists than one who is term-limited so will actually engage in more corruption. While a term-limited legislator may suffer to a degree from lame duck status, the need to continuously seek electoral support is far more damaging to his ability to do what is right for the nation. Politicians who are not term-limited will spend more time doing what is popular than what is necessary. It is far better to have a representative who has only a limited time to enact the policies he envisions, so that he actively seeks to implement his vision, rather focusing on the short-term goal of reelection."
Candidate 3: "Term-limiting legislators insults the intelligence of the electorate. Individuals can make prudent decisions about who to vote for, and it so happens that that decision is often to keep incumbents in power. If the reason for such high reelection rates is due to an uneducated or disaffected electorate, then the problem is not be solved by simply instituting term limits. Rather, such results mean an effort must be made to educate voters and to fight voter apathy. Neither of those things is accomplished by limiting the choice of the voters."
Candidate 4: "Term limits promote greater choice in candidates and protect democracy1. While people may not be able to vote for a legislator again who has reached his limit of service, they can still vote for a continuation of his policies by voting for his chosen successor or for his political party's candidate. Limiting individual politicians to specified terms, however, prevents them from becoming too powerful and damaging the democratic system through efforts at self-enrichment and influence-peddling.

1 Bandow, Doug. 1995. "Real Term Limits: Now More Than Ever". Cato Institute Policy Analysis."
Candidate 5: "The dynamics of party primaries are not the same in all jurisdictions, and efforts at promoting moderate and capable candidates can still be made after the institution of term limits. Furthermore, new politicians may in fact be more willing to work on bipartisan projects, as they are not inculcated in the culture of confrontation that predominates between political parties in many legislatures. For this reason politicians of longer standing might actually be a hindrance to bipartisan compromise. It is far better to allow for a preponderance of political views by making the legislature more open. The best way to accomplish this is clearly to impose term limits."
Candidate 6: "A term-limited legislator suffers from the effects of being a lame duck. A final term legislator will not be able to command the same degree of leverage as one who can potentially serve another term. Building the necessary support for worthy legislation might thus prove far more difficult than it would have had the legislator not been a lame duck. Furthermore, with regard to lobby-group support, a politician on the way out who cannot seek another term has an incentive to favor groups and firms that will place him on their boards, a potentially highly lucrative retirement package for outgoing legislators, paid for often at the expense of the public."
Candidate 7: "If people wish to pursue a career in politics, then it is their right to do so. There is nothing wrong with career politicians so long as they obey the will of their people and accurately represent the desires of their constituents. While there should be no bar to people seeking to enter politics on a temporary basis, placing that form of political participation over a more lasting one makes no sense. Furthermore, career politicians have valuable experience that can be extremely useful in the forming of legislation and the conducting of public business. Term limits destroy this valuable resource by casting people out of the halls of government at a fixed point, regardless of the worth they might still impart to the legislative process."
Candidate 8: "Legislators may gain skill in maneuvering in the legislative arena with time, but they also gain a propensity for power grabbing and self-advancement. Politicians of long standing use their knowledge of the working of the legislature as much for the lobbyists and interest groups, who they prefer to work with rather than young, inexperienced legislators. The power of lobbyists is magnified by the solidity of the channels of political influence created by high rates of incumbency. Term limits actually serve to restrict the power of interest groups, and instead places emphasis on the production of progressive legislation."

A term-limited legislator suffers from the effects of being a lame duck. A final term legislator will not be able to command the same degree of leverage as one who can potentially serve another term. Building the necessary support for worthy legislation might thus prove far more difficult than it would have had the legislator not been a lame duck. Furthermore, with regard to lobby-group support, a politician on the way out who cannot seek another term has an incentive to favor groups and firms that will place him on their boards, a potentially highly lucrative retirement package for outgoing legislators, paid for often at the expense of the public.
