Congressional Republicans are fighting among themselves again, and this time it’s about whether to shut down the U.S. government over Obamacare funding. Some see it as fiscally conservative to defund the new health-care law, while others think holding the nation hostage is just plain insanity.

U.S. Sen. Mike Lee, R-Utah, and 11 other senators sent a letter to Senate Majority Leader Harry Reid, D-Nev., Thursday, putting him on notice they will not be supporting a 2014 continuing resolution that further funds implementing the law. The senators argue that because the administration chose to delay the employer mandate as well as the eligibility verification, it helps prove “the law is a failure.” They call on him to agree that the law, officially known as the Affordable Care Act, cannot be implemented as written.

“This is a matter not only of fiscal prudence, but of fundamental fairness as well,” the letter read. “The president cannot seriously expect to waive Obamacare’s onerous mandates on large businesses, while simultaneously forcing individuals and families to pay to implement an individual mandate the public has opposed since before the law was even passed.”

Americans should not fund the law while the government is refusing to enforce it, the senators stated. The GOP group includes the trio being rumored as potential 2016 presidential candidates: Marco Rubio of Florida, Ted Cruz of Texas and Rand Paul of Kentucky. The senators are also asking Americans to sign the letter to defund Obamacare. That call was echoed in the House of Representatives as more than 60 Republicans have signed a letter to Speaker John Boehner, R-Ohio, asking him to defund the nation’s health-care law, as Politico reported.

However, the idea of causing a government shutdown Oct. 1 over what is already the law of the land appears foolish to some. Sen. Richard Burr, R-N.C., called the conservative effort to link the continuing resolution to the repeal of Obamacare “the dumbest idea I’ve ever heard.”

Similarly, the possibility of using the debt-ceiling issue as part of their game plan is getting no support from others. “No, I don’t support that,” Sen. Roy Blunt, R-Mo., said in an interview with MSNBC, according to the Washington Post. “I don’t support the health-care plan. I think it’s destined to fail. I believe the president keeps postponing it partly because he knows.”

Some fear the mere mention of -- and any action -- on such an idea could create a backlash. The Atlanta Journal-Constitution reported Rep. Tom Cole, R-Okla., told Fox News, “It’s just not helpful, and I think it’s the sort of thing that can create a backlash, that could cost the Republicans majority in the House, which is after all the last line of defense against the president, and could materially undercut the ability of the Republicans in the Senate to capture the majority in 2014, which I think they have a decent chance to do.”

Still, some such as Rubio, who has lost points with conservatives for backing the Senate-passed comprehensive immigration-reform bill, continue to push for defunding the law. Following President Barack Obama’s economic speech in Florida on Thursday, Rubio said Obamacare is the “most pressing economic threat” currently facing the nation. He accused the president of wanting to delay other controversial aspects of the law until after the next election.

“Mr. President, it’s not that Washington has taken its eye off the ball,” Rubio said. “It’s that you refuse to see Obamacare’s failings and, like so many of your policies, when you see a problem, your solution is to throw more money at it. We can’t keep doing this, and we won’t.”