when you put Republicans on the spot and demand specifics about how they’re going to make good on their posturing about spending and deficits, they come up empty. There’s no there there.

While there has been a lot of bluster from the G.O.P. about how we should reduce the deficit with spending cuts, not tax increases, no leading figures on the Republican side have been able or willing to specify what, exactly, they want to cut.

And there’s a reason for this reticence. The fact is that Republican posturing on the deficit has always been a con game, a play on the innumeracy of voters and reporters. Now Mr. Obama has demanded that the G.O.P. put up or shut up — and the response is an aggrieved mumble.