Without in any way impugning his motives, let me state the impact on Warren Buffett personally if the bailout is enacted.
Think of the mortgage securities market as the World Series of Poker. In fact, a great book about it is Liar's Poker, by Michael Lewis. Lewis was a trainee at Salomon Brothers, and he learned phrases like "Big Swinging D___," which describes a swaggering, aggressive mortgage banker. Henry Paulson fits the model.
The best players in this World Series of Poker are the folks at Goldman. They hired Fischer Black and other geniuses back when the markets were first getting going. They have typically had the best squad of geeks around.
Buffett just bought a stake in Goldman. That stake would be a lot more valuable if there were actually a poker game--that is, if mortgage securities were still trading. Right now, they're not trading. So Goldman is sitting there ready to play and no one is ready to play with them.
Along comes Uncle Sam, who wants to take a one-hour lesson in poker and then sit down and play in the World Series with $700 billion in chips. And whaddaya know? Warren Buffett thinks Uncle Sam really has to get in the game.