WASHINGTON — For years, legislation to raise the federal debt limit offered plenty of political theater on Capitol Hill, with the party out of power using it to rail against the party in power. As a senator, Barack Obama said in 2006 that a bill to raise the debt limit was “a sign of leadership failure.”

This time is different, and not only because the parties have switched roles. Now, conservative House Republicans have a virtual veto over a measure to increase the debt ceiling, and some freshmen in both chambers say they worry more about changing the ways of Washington than about getting re-elected.

“Re-election is the farthest thing from my mind,” said Representative Tom Reed, a freshman Republican from upstate New York. “Like many of my colleagues in the freshman class, I came down here to get our fiscal house in order and take care of the threat to national security that we see in the federal debt. We came here not to have long careers. We came here to do something. We don’t care about re-election.”

It is not clear how genuine or widespread that sentiment is in Congress, but regardless, it has upended what President Obama said on Friday had been a “difficult but routine process” in past years.