House Republicans on Friday conditioned funding the federal government for the rest of the year on repeal of President Barack Obama’s signature health reform law — a proposal that will in all likelihood fail in the Senate, thus setting the stage for a familiar budget showdown.

Congress is due to pass a budget plan for the next fiscal year before the end of the month. At the same time, it has to enact legislation to raise the nation’s legal borrowing limit, or debt ceiling, which the Treasury Department expects to hit sometime in the middle of October. Failure to do so would rattle financial markets and could lead to a downgrade of the government’s credit rating if not default.

Opposition Republicans, who are in the majority in the House of Representatives, previously leveraged their support for raising the debt ceiling on austerity measures. Partly as a result, the federal deficit is expected to come in under $1 trillion for the first time in four years.

The party also had to agree to raise taxes, however, to get Democrats to support spending cuts. Republicans’ demand this time — the repeal of President Obama’s biggest first term legislative achievement — may go too far.

House Republicans voted 41 times before to defund the president’s health-care reforms — to no avail. “The Senate will not pass any bill that defunds or delays Obamacare,” the Democrats’ leader in the Senate, Harry Reid, said Friday. The president himself has threatened to veto any bill that strips funds from his health-care plan.

Seasoned Republican lawmakers and many conservative commentators recognize that the effort, which is spearheaded by “Tea Party” legislators who were elected in 2010 or last year, is bound to fail.

“Never issue a threat you’re not prepared to in the end honor and deliver on,” columnist Charles Krauthammer advised in July before predicting, “All the president has to do is wait and they’re going to cave.”

Few Republicans are actually willing to risk leaving the government without funds for next year or default on its debt obligations in order to repeal “Obamacare.”

“What the Tea Party is trying to do is impossible,” said Fox News’ Bill O’Reilly, America’s most popular right-wing television host, on his program Thursday night. He described the enterprise as “destructive” to the small-government cause.

The episode marks an escalation in the struggle between Tea Party Republicans, who champion resistance to the Democrats’ perceived big government agenda at any cost, and moderate or “establishment” lawmakers who rightfully worry that the fight will cost them support in the polls. Hardline Republican voters may sympathize with the effort to derail Obamacare but centrist voters see the party’s fixation on this issue and its uncompromising attitude in general as reckless.

Except for major wins in the House of Representatives in 2010, Republicans have lost three out of the last four last elections. If they are to retake control of the Senate in next year’s midterm elections or the presidency in 2016, Republicans can not afford to be defined by politicians who prioritize ideological purity over electoral success.