Sen. Lindsey Graham (R-SC) says he no longer plans to vote for an energy and climate bill he wrote with Sens. John Kerry (D-MA) and Joe Lieberman (I-CT), because it doesn't allow enough room for new offshore drilling. Angry proponents of the bill, which would institute a carbon cap-and-trade system to lower greenhouse gases, say that Graham has effectively killed any chance the bill will pass this year, or for many years to come. Why did Graham change his mind? (Watch Graham push his climate bill just a few months ago.) Here are three theories:

1. Graham was never serious about the bill
When will Democrats pick up on Graham's "nasty habit of betrayal"? asks Steve Benen in Washington Monthly. He's like Lucy, in Peanuts, "who always pulls away the football and puts Charlie Brown on his ass" — and we, the nation, are Charlie Brown. "If something important needs to get done, and it's entirely dependent on Graham working seriously towards a policy goal in good faith, prepare to be sorely disappointed."
"Lindsey Graham pulls away the football, again"

2. He saw it wasn't going to pass, and saved himself needless pain
"Graham was serious about doing this if he thought it could be done," says Ezra Klein in The Washington Post. But when he saw that a carbon-pricing scheme, already unpopular with his base, wouldn't get the necessary 60 votes in the Senate, fighting for the bill became "foolhardy" politics. In this election year, says Ed Morrissey in Hot Air, even Democrats are reluctant to back what amounts to "an economy-killing energy tax that will stifle what little growth we have at the moment."
"Lindsey Graham and the failure of the 'lone Republican' theory"

3. He's as confused about what to do as the rest of us
Graham's defection means our best hope is an energy-only bill that offers "subsidies to every special interest you can imagine" and "accomplishes very little," says Kevin Drum in Mother Jones. But that's what Americans say they want, according to polls — large majorities believe in global warming, and want the government to do something, as long as it doesn't involve taxing anybody. Thanks to Graham, we're "getting exactly the government we deserve. A government of children."
"R.I.P. climate legislation"