Via National Journal:

The White House on Thursday dismissed as political mischief Senate Minority Leader Mitch McConnell’s offer to bring President Obama’s fiscal cliff plan to a vote on the floor, conceding the proposal would not receive the 60 votes needed to overcome a filibuster.

“We don’t have 60 votes in the Senate,” White House press secretary Jay Carney said, adding the White House was “very confident” that Democrats support the principles outlined in Obama’s plan, which has met with derision among Republicans.

Carney called McConnell’s Wednesday challenge “the kind of political games that aren’t serious.”

The Senate this summer passed the Democrats’ bill allowing rates to rise on households above $250,000, but only because Republicans agreed to a straight majority vote.

Carney also said the White House had concluded that Obama could not invoke the 14th Amendment, which some Democrats argued during last year’s debt-ceiling fight could permit the president to circumvent Congress and borrow past the statutorily imposed limit, to avert default.