Sens. Claire McCaskill (Mo.) and Bill Nelson (Fla.), two Democrats facing tough races this year, on Thursday declined to rule out support for an across-the-board extension of the rates.

“If you want to do something in the spirit of compromise, you don’t start out by saying, ‘I refuse to do this’ or ‘I refuse to do that,’ ” said McCaskill. “It’s not my preference to extend tax cuts to multimillionaires — that’s not my preference — but I want to keep every option open in the spirit of compromise.”…

Democratic leaders fear that cutting a deal similar to the one Obama struck with McConnell in 2010 to temporarily extend all of the Bush rates would undermine their leverage in deficit-reduction talks next year.

“Just extending it all isn’t very attractive,” said Senate Budget Committee Chairman Kent Conrad (D-N.D.), who does not support a yearlong across-the-board extension. “You take the pressure off of doing what really needs to be done.