Thus, the CR vote may be the last chance to stop Obamacare.

Senator Ted Cruz and Representative Tom Price are expected to introduce an amendment that would prohibit the use of any funds authorized by the CR “to carry out any provision of the Patient Protection and Affordable Care Act.” In addition, a dozen Republican senators (Cruz, Mike Lee, Marco Rubio, Rand Paul, Jim Risch, Jim Inhofe, David Vitter, John Thune, Jeffrey Chiesa, Mike Enzi, Debra Fischer, and Chuck Grassley) have signed a letter pledging not to vote for any CR that includes funding for Obamacare.

Some Republicans have taken a decidedly different position. Representative Tom Cole, a deputy majority whip, calls efforts to defund Obamacare “a temper tantrum” by House conservatives. Senator Richard Burr of North Carolina says it’s “the dumbest idea” he’s ever heard. And Senator Bob Corker calls it “silly.” Reportedly, the GOP leadership in both chambers is actively working against the idea.

In some ways, this seems like an obvious fight for Republicans to pick. According to public-opinion polls, support for Obamacare is near an all-time low. Democrats and their constituencies are defecting in droves: Earlier this month, 35 Democratic congressmen voted in favor of eliminating the employer mandate, and 22 voted to kill the individual mandate as well. The Teamsters, the United Food and Commercial Workers, and other unions have written to the administration demanding changes to the law. And even Democratic lawmakers in Massachusetts have voted to seek a waiver from some of Obamacare’s requirements.

But critics of tying Obamacare to the CR have a point as well. Republicans are very likely to pay a political price for any government shutdown. Moreover, it is hard to see a path to victory. It is almost inconceivable that President Obama will abandon the signature accomplishment of his presidency. And further, as a matter of policy, Republicans trying to defund Obamacare may simply be beating their heads against a stone wall. As Senator Tom Coburn put it: “I’d be leading the charge if I thought this would work. But it will not work.”

Still, sometimes lawmakers really should stand for something more important than their own reelection. Obamacare is such a fundamental transformation of the American health-care system, and its consequences for patients, providers, taxpayers, and the economy are so grave, that if this is not an issue that Republicans are willing to lose their jobs over, what is?

Alternatively, even if the president will never accept the repeal of his health-care law, a year’s delay might be a feasible compromise. After all, the president has already delayed the employer mandate and other portions of the law. There are considerable doubts as to whether other parts of the law, such as the exchanges, will be fully operational. A great many Democrats might welcome more time to work through some of those “glitches.”

At the very least, Republicans ought to try something. As Senator Lee told Fox News, “Maybe we can’t repeal [Obamacare] right now, but we can delay its funding. And if we can delay it, we can stop its consequences, at least for now.”

Whether that will happen remains to be seen. Asked if Republicans had the courage to fight for defunding, Rand Paul replied gloomily, “Honestly? Probably not.”

Oh well. Perhaps they do have the courage to pass a symbolic resolution to repeal the health-care law for the 40th time.

— Michael Tanner is a senior fellow at the Cato Institute and author of Leviathan on the Right: How Big-Government Conservatism Brought Down the Republican Revolution.