After last week’s assault on the US Capitol by pro-Trump rioters, there have been lots of calls from Republicans for “unity” and “reconciliation.”

The pleas for unity, however well-intentioned, obscure a crucial fact: This is not a bipartisan crisis. The Republican Party welcomed Trump into their ranks and indulged and excused him for four years. They nurtured the movement that led to the attack on the Capitol.

Even after the Capitol was violently sacked, even after at least five people were killed, a poll showed that 45 percent of Republicans support the invasion. That means millions upon millions of Americans see no problem in disrupting the peaceful transfer of power, a bedrock of constitutional democracy. And mere hours after the crisis at the Capitol, nearly 150 Republican lawmakers formally objected to the results of the 2020 election anyway.

So that’s where we are.

Geoffrey Kabaservice is the director of political studies at the Niskanen Center and the author of Rule and Ruin, a 2012 book that surveyed the ideological descent of the GOP from the 1950s to the rise of the Tea Party in early 2009. It’s an interesting look at how conservative politics in America has always been prone to reactionary spasms, but explains how something fundamentally different happened with the Tea Party more than a decade ago.

We discussed what made the Tea Party different from previous conservative upwellings, how it was a harbinger of the MAGA movement, how the Gingrich revolution in the ’90s destroyed Congress as an institution, and if he sees a viable path to de-radicalization for the Republican Party. Ultimately, he’s more sanguine than I am about the possibilities, but we’re equally pessimistic about the consequences if there isn’t a real reckoning in the GOP.

A lightly edited transcript of our conversation follows.

Sean Illing

Would you say that the Republican Party, as it exists today, is a radical party?

Geoffrey Kabaservice

Yes. As currently constituted, it’s a radical party. It’s come an awful long way from the conservative precepts and principles it used to hold. And at this point, it’s largely the instrument of one man’s will. And that man, Donald Trump, does not have a commitment to electoral democracy or the constitutional order. So yes, that makes it a radical force.

Sean Illing

This is a hard question to answer, I get that, but what are the most significant forces or moments that brought the GOP to this dark place?

Geoffrey Kabaservice

I think of American conservatism as a series of lost causes that carried on well beyond their expiration date. We can start with the William F. Buckley era of intellectual conservatism in the ’50s and beyond, and that was really carrying on the lost cause of the original “America First” committee, which had tried to keep the United States out of World War II, as well as Joseph McCarthy’s anti-communist movement.