THE SENATE Republican leadership yesterday yielded to a stubborn Sen. John McCain and others and agreed to bring up a campaign finance reform bill this fall. The equally resistant House Republican leadership earlier agreed under similar pressure to do the same.

An agreement to proceed is a long way from victory. At the end of the process, Senate opponents still will be able to filibuster, as they did twice to defeat a similar bill in the last Congress. But this is a Congress that has done so little that an agreement even to go through the motions of legislating is news. And the agreement creates at least a parliamentary opportunity for enactment, whatever the underlying odds. So it's a gain.

Sen. McCain, a long-shot candidate for the Republican presidential nomination, had threatened, absent an agreement, to tie up the Senate by offering his bill as an amendment to the successive appropriations bills that the leadership wants to pass before the August recess. The leaders can now proceed with those, and no matter that they, too, constitute a charade of sorts.

The Republicans are pretending that they can keep total appropriations within limits that even their own appropriators say are unrealistically low. They don't want to breach the limits, because to do so would be to leave less room for a tax cut. But they don't want to adhere to the limits, either. They just want the Democrats to join them in the breakout ahead to share the blame. The bills that are meanwhile being passed are mainly place holders awaiting a deal later in the year.

The campaign finance bill that Mr. McCain is pushing has been narrowed. It would mainly ban the fiction called soft money -- the use of the national party organizations to raise and spend on behalf of their candidates funds that the candidates are forbidden to raise and spend themselves. An earlier version would also have banned related devices -- the use of supposedly independent organizations to do the same thing. Critics complained that this could infringe on free speech, and Mr. McCain dropped it to strip them of the argument.

A soft-money ban is thought to have majority support in both houses. That's not enough in the Senate, where 60 votes are required to break a filibuster. The leadership has agreed to drop some of the procedural devices that can be used to bottle up a bill, but not all. A soft-money ban is the least that ought to be imposed on a system in which office has ceased to be won so much as bought. That's what the Senate can now decide this fall.