Lofgren expands upon these themes in “The Party Is Over,” his fast-moving, hard-hitting, dryly witty book-length account of the radicalization of his party, the failures of Democratic rivals and the appalling consequences for the country at large. Like the essay that inspired it, it is forceful, convincing and seductive enough to prompt one to follow along, even when the intellectual terrain begins to look familiar.

When Lofgren started his career in the early 1980s, he writes, the GOP had an influential moderate wing — “politicians of the old school, who could reach across the aisle, make a deal, and stick to it” — and bipartisan coalitions were still possible. Kasich could team up with liberal Democrats such as Ron Dellums to rein in boondoggles such as the B-2 bomber program. Even a divisive figure such as Sen. Barry Goldwater cooperated with Rep. Bill Nichols of Alabama, the senior Democrat on the House Armed Services Committee, to push Pentagon reform and “wouldn’t have dreamed of issuing a partisan jerimiad” against him.

So what happened? Lofgren joins a bipartisan intellectual consensus that Newt Gingrich is largely to blame by destroying the old committee system, concentrating power in the speaker’s office and practicing “scorched-earth tactics” that were carried on by successor Tom DeLay. After Sept. 11, 2001, “things got much worse” as Karl Rove and other party operatives sought to paint Democrats as un-American appeasers opposed to heartland morality. “By the 2010 midterm elections,” Lofgren declares, “the party had collectively lost its mind.”

For those who’ve been paying attention, much of what follows will be familiar. The notion that the GOP is pushing policies that are enriching the wealthy at the expense of the middle class was one of the pillars of Michael Lind’s book “Up From Conservatism,” published at the end of Bill Clinton’s first term. The corrosive effect of radicalized religion on the party was a central theme of Kevin Phillips’s “American Theocracy” (2006), while Thomas Frank’s “What’s the Matter With Kansas” detailed the GOP’s use of social issues to rally the people whom Lofgren calls “low information voters” to embrace leaders whose policies are dissolving their means of survival. Rolling Stone’s Matt Taibbi has been tirelessly chronicling the bipartisan betrayal of most Americans’ interests for years, while Lawrence Lessig fleshed out the role moneyed interests have played in his book “Republic, Lost.”

Like many of these writers, Lofgren is little impressed with the Democrats, who, he says, “have almost entirely ceased to have any core beliefs at all.” They, too, are carrying water for plutocrats, wasting the nation’s treasure on divisive foreign wars and trampling on the Constitution by accepting, under President Obama, the consolidation and expansion of Bush-era executive powers to monitor, torture, detain or even assassinate persons without charge. Democrats aren’t “an extremist party like the GOP,” Lofgren grants, but starting in the 1990s they moved rightward and “abandoned the practices of their old beliefs while continuing to espouse them in theory,” leaving the United States with an unhealthy “one-and-a-half party system.” He thinks this a poor strategic choice, “because if people want a Republican, they will vote for the real thing.”