Congressional term limits have polled above 70% support since the 1990s. They were central to Newt Gingrich's 1994 Contract with America. They're regularly invoked by outsider candidates of both parties. And in more than thirty years of serious political attention, Congress has never come close to passing them.
The Constitutional Barrier
In U.S. Term Limits v. Thornton (1995), the Supreme Court ruled 5-4 that states cannot impose term limits on their members of Congress — the qualifications for serving are set in the Constitution and cannot be supplemented by state law. Federal term limits would therefore require a constitutional amendment: passage by two-thirds of both chambers and ratification by three-fourths of states. The same members whose terms would be limited would have to vote to limit themselves.
The Case For
Long tenure produces an insular political class disconnected from constituents and dependent on lobbyists and seniority. Term limits would force regular turnover, reduce incumbency advantages that make most races non-competitive, and break the seniority system that concentrates power in long-serving members. State legislative experience with term limits finds some evidence of reduced careerism and more policy focus — though whether these shifts are improvements depends on what you think legislatures are for.
"Term limits are attractive because they promise to change the people without changing the system. But it's the system — fundraising requirements, partisan incentives, committee structure — that shapes behavior. New people in the same system produce similar results."
The Case Against
Term limits shift power to those who aren't limited: staff, lobbyists, and executive branch officials whose expertise outlasts any legislator's. A junior member who can't build seniority is more dependent on outside expertise — in practice often industry lobbyists. Voters already have the theoretical ability to impose their own term limits through elections; the counterargument is that incumbency advantages and gerrymandering make this practically limited in most districts. The deeper issue: when the people most affected by a reform are the same people who must enact it, the reform reliably doesn't happen.