The Senate will return from Easter vacation with nuclear options on its mind. Republicans seem determined to change the rules so Democrats will no longer be able to stop judicial nominations with the threat of a filibuster. If they're acting out of frustration, it's understandable. In the past we've been frustrated when legislators tried to stop important bills from passing by resorting to the same tactic. The filibuster, which allows 41 senators to delay action indefinitely, is a rough instrument that should be used with caution. But its existence goes to the center of the peculiar but effective form of government America cherishes.

Since George W. Bush first became president, Democratic senators have used the filibuster 10 times to block the confirmation of nominees for federal court judgeships. They chose their targets cautiously -- more than 200 other nominees were confirmed, some of them men and women whose records were extremely conservative. But surely it is not a matter of life and death to the White House if, for instance, a former lobbyist for mining interests with a reputation for anti-environmentalism cannot get a seat on the federal bench out West. The president might have taken this opportunity to fulfill his long-deferred promise to be a uniter, and replaced the rejected nominees with other candidates from the very large pool of competent people available. Instead, Mr. Bush has drawn a line in the sand and resubmitted some of the same unworthy nominees. If the Democrats resist, the Republican leaders have vowed to change the rules and eliminate the right of filibuster for judicial nominations.

They may not have the votes to make this happen. Many of the wisest Republicans are well aware that their leaders are playing a dangerous game and that they are doing it for frivolous reasons. The judicial nominees can easily be replaced. But the sense that there are certain rules that all must play by, whether to their advantage or not, is something that cannot be restored. Senators need only to look at the House to see what politics looks like when the only law is to win at any cost.

The Senate, of all places, should be sensitive to the fact that this large and diverse country has never believed in government by an unrestrained majority rule. Its composition is a repudiation of the very idea that the largest number of votes always wins out. The members from places like Rhode Island, Maine or Iowa know that their constituents are given a far larger say than people from New York simply by virtue of the fact that each state has two votes, regardless of population. Indeed, as a recent New Yorker article pointed out, the Democratic senators who have blocked that handful of judicial nominees actually represent substantially more Americans than the Republican majority that wants to see them passed.