“When the president stands up and says ‘I will not negotiate,’ that’s not particularly tenable either. . . . People look at the debt ceiling as, ‘If we’re that broke, why are we asking to be able to put more money on the credit card?’” he told me.

Senior GOP lawmakers are banking on receiving modest support for the debt-ceiling bill from vulnerable Democrats, which will help put the heat on Obama. That will combine with the well-known concerns that many Democrats have about the disastrous Obamacare roll-out. (Senator Joe Manchin of West Virginia came out in favor of delaying the individual mandate Wednesday morning.)

“The best thing we can do to turn up the heat on the president — and Senate Democrats — is to pass a House bill that couples the debt limit with popular spending cuts and reforms to get our economy going again and create jobs,” said Michael Steel, Boehner’s spokesman.

But Democrats are certainly talking a big game. In a number of interviews with senior lawmakers and key aides on the left side of the aisle, they too said they think their adversaries will cave.