Congressional Republicans have little interest in threatening a government shutdown or withholding votes on the debt ceiling as leverage to defund Obamacare — but only because they view the strategy as a political loser.

Republicans intend to extract concessions other than the defunding from President Obama and Senate Democrats in exchange for votes to raise the nation's borrowing limit and advance a continuing resolution needed to continue funding for the government beyond Sept. 30, the end of the fiscal year. Repealing Obamacare's medical device tax is high on the GOP's list of priorities, as is winning administration approval for the Keystone XL pipeline — just a few items Republicans might seek to negotiate.

Public polls show that a majority of Americans either oppose Obamacare or view it unfavorably. But threatening to force a government shutdown during fiscal negotiations has historically been a risky play, and Republicans concluded that employing this strategy could generate sympathy for the president and broader support for Obamacare that would make it even harder to repeal.

"The problem is: What's the endgame?" said the chief of staff for a House Republican.

Republicans unanimously oppose Obamacare and have voted dozens of times to repeal it, but they remain hesitant use to use the continuing resolution and debt ceiling negotiations to achieve defunding. That sentiment pervades both the House and Senate GOP, even though 66 House Republicans and about a dozen Republican senators have signed letters backing the defunding of Obamacare.

Republican sources said their rank and file could still shift positions depending on what they hear from constituents over the August recess.

Rep. Jim Jordan, R-Ohio, an ardent conservative opponent of the president's health care reforms, said Republicans are still discussing the most effective way to derail the full implementation of Obamacare. He and his colleagues are still trying to determine which strategy would give the GOP the best chance to win over the public and succeed legislatively on Capitol Hill.

"You're always looking for the right way to do the right thing," Jordan said. "No decisions have been made on what the best way is to prevent this bad law from happening."

House Speaker John Boehner, R-Ohio, declined Thursday to talk about strategies to defund Obamacare or how it may link to upcoming fiscal negotiations.

"No decision has been made about how we're going to deal with the CR," Boehner said.

The fight to force Obama to effectively sign a repeal of his signature health care law is being driven by fewer than a dozen Republicans in both chambers, and a few influential conservative outside groups, including the Club for Growth and Heritage Action for America. Sens. Ted Cruz, R-Texas, Mike Lee, R-Utah, and Marco Rubio, R-Fla., are leading the charge, along with Reps. Tom Graves, R-Ga., Mark Meadows, R-N.C., and Jordan.

Lee, who hatched the plan to link Obamacare and the continuing resolution, believes the strategy is sound. The Tea Party favorite is encouraged by polling that shows a drop in public support for Obamacare among Obama's fellow Democrats and complaints about the reforms coming from organized labor.

"The American people are overwhelmingly against it, so what we want to do is fund government, not Obamacare," Lee said. "I think it is the right strategy, I don't mean to suggest it's easy."

One House Republican, who requested anonymity to speak candidly, said he has supported shutting down the government in the past and would do so again. But this congressman does not see a path to political victory, one that results in a critical mass of voters siding with the GOP and demanding that Obama relent to avoid the government shutdown.

It's a concern that divides the GOP ranks.

In one camp, members support chipping away at the health care law piece by piece, using legislation such as the recent House GOP bill that would delay the onset of the individual mandate. Coming on the heels of Obama's unilateral move to delay the employer mandate until 2015, that bill garnered the support of several Democrats, and many Republicans believe attacking Obamacare this way would help build overwhelming public support.

The other camp wants a full repeal or nothing. These Republicans fear that dismantling the law will be impossible after next year, when government starts paying out subsidies to help millions of people buy health insurance.

"Republicans don't want to play brinkmanship," Sen. Ron Johnson, R-Wis., said. "So, we are kind of grappling with, what's the best way to communicate that to the American pubic to gain the support so that we can stop this thing before it takes root."