The bill, introduced on Monday, is running a two-week-long gauntlet on the Senate floor, with scheduled votes every three hours on this amendment or that, most of them put forth by reform opponents looking to kill McCain-Feingold by diluting it to death.
Tuesday, McCain and Feingold cut their first deal, with Pete Domenici, over the so-called "millionaire's exemption" allowing the opponent of a self-financed candidate to raise extra money to keep up. Thus blessed, the amendment passed 70-30, and McCain-Feingold acquired its first alteration but probably not its last.
Will McCain and his bill's supporters continue to make compromises without compromising too much? TIME Washington correspondent Jay Carney lays out the big picture.
TIME.com: With so much debate and so many amendments and campaign finance being complicated enough already is there a way to chart McCain-Feingold's progress without reading all the fine print?
Jay Carney: The key is going to be the amendments. You have to see which amendments McCain is actively lobbying against, both on the Senate floor and in conversations with his colleagues what kind of changes to his bill he can live with, and whether his supporters stay with him.
The millionaire exemption was a good example. Monday, he was against it, and it was defeated narrowly. Tuesday, after negotiating some changes Monday evening, McCain dropped his objections and the amendment passed. That's a sign his support is holding, that he still has some control over the bill's fate.
But also that compromises are inevitably going to be made.
JC: Right. The question is, what does this bill look like when it's finished and whether Bush will sign it. With Bush in the White House, if this thing goes in looking like McCain-Feingold and gets so adjusted that it looks more like the Hagel bill every day, then it's very likely we'll have some kind of campaign finance reform. (Nebraska Senator Chuck Hagel is promoting a softer soft-money bill.)
Then we'll see whether McCain can live with it, or whether he'll feel that the evils of the system have just been further codified. But it's important to remember that even with all the publicity over the Breaux defection (Louisiana Senator John Breaux declared his opposition to the bill last week), and all the rumblings on the Democratic side, McCain-Feingold still has the votes to pass the Senate.
TIME.com: And if it comes through still looking like McCain-Feingold, will Bush sign it?
JC: We don't really know. Bush would probably prefer that nothing come out of the Senate at all, and after that he'd much rather have watered-down reform like Hagel's. But there's also the option of signing some version of McCain-Feingold, and letting it be tested by the courts, on the theory that it would be ruled unconstitutional on free-speech grounds.
Are these two weeks campaign finance reform's last chance?
JC: The issue itself will probably never die, but for McCain and Feingold personally, this is sort of deemed to be their big moment. If it goes down again, after getting full-Senate debate, they may have to find some new sponsors.