Ideas are not responsible for the people who believe them, but when evaluating Senate Majority Leader Harry Reid's ideas for making the Senate more like the House of Representatives, consider the source. Reid is just a legislative mechanic trying to make Congress' machinery efficiently responsive to his party's progressivism. And proper progressives think the Constitution, understood as a charter of limited government, is unconstitutional.

They think the "living" Constitution gives government powers sufficient for whatever its ambitions are, enabling it to respond quickly to clamorous majorities. Hence, the progressive campaign to substantially weaken the ability of senators to use filibusters to delay action.

Until 1917, it was generally impossible to stop extended Senate debates. Then - during the administration of Woodrow Wilson, the Democrats' first progressive President - the Senate adopted the cloture rule whereby debate could be ended by a two-thirds majority vote. In 1975, the requirement was lowered to three-fifths. If there is now another weakening of minority rights, particularly by a change brought about by breaking Senate rules, the Senate will resemble the House. There the majority controls the process, and the disregarded minority can only hope to one day become the majority and repay disregard in kind.

Wilson was the first President to criticize the American founding, which he did because the Constitution bristles with delaying and blocking mechanisms, especially the separation of powers. The point of progressivism, say its adherents, is to progress up from the Founders' fetish with limiting government and restraining majorities. Hence progressives' animus against the filibuster, which protects minority rights by allowing for the measurement of intensity as well as mere numbers.

Since there have been 50 states, Republicans have never had 60 senators. Democrats have had that many after 11 elections. Both parties are situational ethicists regarding the filibuster - in 2005, a Republican Senate majority threatened to forbid filibusters of judicial nominees during George W. Bush's administration. It is, however, when filibusters impede the liberal agenda that excited editorials are written and solemn seminars are convened to deplore the "constitutional crisis" of a "dysfunctional Congress."

Recourse to filibusters has increased in tandem with, and partly because of, the 70 times Reid has used a parliamentary device ("filling the tree") to limit and even deny the minority's right to offer amendments to legislation. Furthermore, 69 times Reid has bypassed committees, bringing bills written in private directly to the Senate floor without any Republican participation. The filibuster is a means whereby the minority can give an overbearing majority an incentive to compromise. Yet progressives simultaneously complain about the filibuster and the absence of compromise.

Under Senate rules, it takes 67 votes to change the rules. Reid, however, may decide that in January, on the first day of the new session, the supposedly "new" Senate can adopt new rules by a simple majority. This ignores the fact that the Senate, unlike the House, is a continuing body because, with staggered elections, no more than one-third of its members can be new - and not nearly that many ever are new - at any time.

The Senate can adopt new rules by a simple majority only by ignoring its long-standing rules. In the 2005 argument about filibustering judicial nominees, Sen. Joe Biden believed, or was told he believed, this "arrogance of power" ignored the fact that "the Senate is not meant to be a place of pure majoritarianism."

Four House Democrats have asked a federal court to declare Senate filibusters unconstitutional. They say the supermajorities needed to end a filibuster infringes the principle of majority rule and dilutes the votes of members of the House. The court has many reasons, each sufficient, for refusing to so rule, including these two:

The Constitution says each house of Congress "may determine the rules of its proceedings." Also, the Constitution requires of Congress six supermajorities (for ratifying treaties, proposing constitutional amendments for ratification, impeachment convictions, overriding vetoes, expelling members, and removing an incapacitated President who objects to removal). It is a perverse non sequitur to say that if the Constitution does not mandate a particular supermajority, it is impermissible.

Conservatives believe that 98 percent of good governance consists of stopping bad - meaning most - ideas. So conservatives can tolerate liberal filibusters more easily than liberals, who relish hyperkinetic government, can tolerate conservative filibusters. Come January, 21 of Reid's 55 Democrats will have come to the Senate in 2009 or later. They have never been in the minority. They must remember this: Some day they may be.

George Will's email address is georgewill@washpost.com.