Senate Democrats have reintroduced legislation that would impose 18-year term limits on future Supreme Court justices, reviving a proposal they first unveiled in 2023 as part of a long-term push to reshape the nation’s highest court. The proposal, led by Sen. Sheldon Whitehouse, D-R.I., faces little chance of advancing in the GOP-controlled Congress. But Whitehouse and the bill’s co-sponsors say reintroducing the legislation is part of a longer-…