With unrestrained glee, Republicans are using the calamitous debut of the Affordable Care Act as their latest justification for undermining all of health care reform. But they’re not stopping there. The Obama administration’s fumbling is apparently a good excuse for them to do nothing on immigration reform, on a budget agreement, and on any other initiative coming out of the White House.

“We don’t want a repeat of what’s going on now with Obamacare,” said Eric Cantor, the House majority leader, explaining last week why party leaders would not allow the Senate’s immigration bill to come to a vote, or even to be the subject of negotiations.

Their opportunistic theme is clear: If you can’t trust President Obama on this issue, how can you trust him on anything else? Unquestionably, the White House handed them this gift through two kinds of incompetence: the technical failure of the health-exchange website, and the political failure of the president in falsely promising that no one would lose an insurance policy they already had.

But just as these blunders are not the end of the health reform, they will also, in the end, not stop the long march to immigration reform, more jobs or desperately needed improvements to education, transportation and other fundamental functions. The House minority leader, Nancy Pelosi, was right to urge Democrats on Sunday not to be “knocked for a loop” by the Republican feeding frenzy. Most people, she said on NBC News’s “Meet the Press,” still support progressive goals like guaranteed health insurance, a humane path to citizenship for immigrants, background checks for gun ownership and ending workplace discrimination.