WASHINGTON — For the Republicans who despise President Obama’s health care law, the last few weeks should have been a singular moment to turn its problem-plagued rollout into an argument against it. Instead, in a futile campaign to strip the law of federal money, the party focused harsh scrutiny on its own divisions, hurt its national standing and undermined its ability to win concessions from Democrats. Then they surrendered almost unconditionally.

“If you look back in time and evaluate the last couple of weeks, it should be titled ‘The Time of Great Lost Opportunity,’ ” said Senator Lindsey Graham of South Carolina, among the many Republicans who argued that support for the health care law would collapse once the public saw how disastrous it really was.

“It has been the best two weeks for the Democratic Party in recent times because they were out of the spotlight and didn’t have to showcase their ideas,” Mr. Graham added.

Now, near the end of a governing crisis that crippled Washington and dismayed a nation already deeply cynical about its political leaders, Republicans are struggling to answer even the most basic questions about the cause and effect of what has transpired over the last few weeks.