Then there are those taking what they call a pragmatic approach by accepting the law, if grudgingly, and moving on. This group includes Govs. Chris Christie of New Jersey and Scott Walker of Wisconsin, who says a shutdown would violate the public trust.

"The government we have should work, so that's why I don't believe we should shut the government down," Walker told reporters at the Michigan conference.

The Republican-controlled House passed a short-term spending plan Friday that would continue funding government operations through mid-December while withholding money for the health law.

Some GOP lawmakers also advocate holding back on increasing the nation's borrowing limit, which could result in a first-ever default, unless the law is brought down.

Obama used his weekly radio and Internet address Saturday to scold "a faction on the far right" of the Republican Party, and he said he would not allow "anyone to harm this country's reputation or threaten to inflict economic pain on millions of our own people, just to make an ideological point."

While attending the Michigan conference, Paul said Republicans could force a vote in both houses of Congress, then negotiate changes to legislation in a joint conference committee. But, he added, time is running out.

Less than one-quarter of Americans approve of the job Congress is doing, about the same as approve of Republicans in Congress, according to recent national polls. Democrats poll slightly higher, and large majorities disapprove of the work of both.

Yet, only about a third of Americans say they approve of the health care act.

Christie has accepted for his state key provisions of the law, yet campaigned on behalf of candidates who support dismantling it. He has taken no public position on whether to fight the law to the point of government shutdown.

"He is either unwilling or unable to speak up against these guys," Democratic National Committee spokesman Mike Czin said.

Michigan Gov. Rick Snyder, hosting the conference where Paul, Walker and Louisiana Gov. Bobby Jindal spoke Saturday, said a shutdown "reflects poorly on the national political culture."

Bush was more pointed. He said Republicans would be guilty of overplaying their hand if they passed a spending measure that did not include money for the health care law.

Noting that Republicans control only the U.S. House in Washington, or "one-half of one-third of the leverage" in the capital, Bush said Wednesday in Washington there "needs to be an understanding of that, or, politically, it gets quite dicey" for the GOP.

Cruz said concerns that voters would blame Republicans for a shutdown are unfounded.

"If history is a guide, the fear of deep political repercussions — I don't think the data bear that out," he said.

Republican lawmakers and Democratic President Bill Clinton failed to agree on spending in 1995, which resulted in two partial government shutdowns.

Clinton was re-elected the following year, but Cruz noted that Republicans held the majorities in both the House and Senate in 1996 and 1998, and collaborated with Clinton on spending cuts and other changes that preceded economic expansion.

Paul and Jindal are attempting to create some daylight between themselves and their would-be rivals. Paul may consider a shutdown dumb but says the fight over the health care law is worth having.

"I am for the debate, I am for fighting," Paul said. "I don't want to shut the government down, though. I think that's a bad solution."

Jindal, who opposes the health law, has said Republicans need to be "more than the party of 'no'" but that it's a bad idea to take any option off the table, including government shutdown.

"I don't think as Republicans we should be negotiating with ourselves," he said in an Associated Press interview, but stopped short of criticizing Paul for his comments.