NEW YORK — I have sometimes been described as a centrist. And I freely admit to believing that neither side of the political spectrum has a monopoly on wisdom or virtue. But sometimes, reality points firmly in one direction. Watching the machinations in Washington over the past two weeks, it is now impossible to talk about how both political parties are to blame for the country’s gridlock.

Consider what just happened on immigration, an issue ripe for resolution. A majority of Americans support granting citizenship to illegal immigrants — by 81 percent in the most recent CNN poll — as well as enhanced border controls. The leadership of the Republican Party in both houses of Congress talked about a comprehensive reform package that would create a lengthy waiting time for citizenship — 13 years — and couple this with tougher enforcement. Most Democrats were willing to accept this compromise.

But it became clear to the Republican leadership that even this would be unacceptable for many tea party Republicans. So on Jan. 30, party leaders circulated a new proposal that took away any prospect of a special path to citizenship for illegal immigrants, no matter how long they waited. Instead, these people would merely be given legal documents allowing them to work and pay taxes. This was a huge concession to tea party activists and seemed unlikely to go anywhere. Democrats had been firmly against the concept of permanent second-class status for illegal immigrants. A majority of the public opposes it as well.

But within a few days, President Obama took the opportunity of an interview with CNN to say he was “encouraged” by the proposal. “I genuinely believe that Speaker Boehner and a number of House Republicans, folks like Paul Ryan, really do want to get a serious immigration reform bill done,” he explained.

Every Democrat I spoke with hated the idea, for moral and political reasons. Most were surprised by Obama’s concession. So what happened? A few days later, John Boehner explained that even his new plan was a nonstarter and immigration reform was dead.

His explanation was that no one trusted Obama to enforce the laws. But in fact, the Obama administration has enforced immigration laws ferociously. It deported more than 400,000 people in 2012, two and a half times the number in 2002. In 2002, for every two people removed from the country, 13 became legal residents. In 2012, for every two removed, just five became residents. For these reasons, as well as the recession, the number of illegal immigrants has not increased in several years.

It’s possible that the latest debt ceiling circus will change things. Yet, Harvard University’s Theda Skocpol points out in an essay in the journal Democracy that commentators have been proclaiming the decline of the tea party for several years now. Still, it continues to exert a powerful influence on the Republican Party. It has two things going for it — immense grass-roots energy and the breakdown of authority within Congress in general and the Republican Party in particular.

Skocpol writes that in the hundreds of interviews she conducted when writing a book on the tea party (with Vanessa Williamson), she found that “fiscal conservatism is often said to be the top grass-roots tea party priority, but Williamson and I did not find this to be true. Crackdowns on immigrants, fierce opposition to Democrats, and cuts in spending for the young were the overriding priorities we heard from volunteer tea partiers, who are often, themselves, collecting costly Social Security, Medicare, and veterans benefits to which they feel fully entitled as Americans who have ‘paid their dues’ in lifetimes of hard work.”

This suggests a bleak future for getting anything done in Washington. Immigration was supposed to be ripe for common-sense reform. The public is for a compromise solution, policy wonks have proposed ways to make it work, the U.S. Chamber of Commerce supports it, the country’s leading technology firms have been clamoring for one, senior Democrats and Republicans are in favor. And yet it couldn’t get past the central problem in Washington today — the extreme and obstructionist faction within the Republican Party.

The next time someone blames “both sides” for Washington’s paralysis or issues a bland call for “leadership” to get us out of it, remember the case of immigration.

Fareed Zakaria is a columnist with the Washington Post Writers Group.