At the Finance committee hearing, Lew met a buzz saw of incredulity from Republicans, who said the bigger problem was the soaring costs of benefit programs like Social Security and Medicare and the long-term budget deficits the country faces. Many expressed doubt about Lew's description of the consequences of default.
The senior Republican on the panel, Sen. Orrin Hatch of Utah, accused the Obama administration of "an apparent effort to whip up uncertainty in the markets." And veteran Sen. Mike Enzi, R-Wyoming, said, "I think this is 11th time I've been through this discussion about the sky is falling and the earth will erupt. Wyoming families aren't buying these arguments."
Replied Lew, "After they run up their credit card, they don't get to ignore it."
Lew also rejected GOP suggestions that in the event federal borrowing authority expires, the government could use the dwindling cash it has to make payments to debt holders and other high priority needs. He said federal payment systems are not designed to prioritize and said he didn't believe such an approach was technically possible.
"I think prioritization is just a default by another name," Lew said.
He also fended off attempts by the top Republican on the committee, Sen. Orrin Hatch of Utah, and other GOP senators to learn how long a debt limit extension the president would like to see.
"Our view is this economy would benefit from more certainty and less brinksmanship. So the longer the period of time is, the better for the economy," said Lew, who also repeated Obama's willingness to accept a short-term extension for now.
The frustrating standoff in Washington is weighing down each side's poll numbers, but Republicans are taking the worst drubbing. A Gallup poll put the approval rating for the Republican Party at a record-low 28 percent. Polls have consistently said the Republicans deserve the greater share of blame for the shutdown.
Associated Press Writers Alan Fram, Stephen Ohlemacher, David Espo, Donna Cassata and Martin Crutsinger contributed to this story.