Republicans hit rock bottom in 1964. Lyndon Johnson crushed Barry Goldwater by a record vote margin, and after ceding 36 House seats, the GOP was outnumbered 2 to 1 in both chambers of Congress. Already humiliated by the electorate’s rebuke of Goldwater’s far-right ideology, his acolytes watched in horror as Senate Minority Leader Everett Dirksen and other GOP standard-bearers allied with liberals to enact civil rights legislation and Johnson’s Great Society agenda.

In three previous volumes, noted historian Rick Perlstein portrayed this epoch as the zenith of a liberal consensus and the origin of the conservative movement that came to dominate American politics. Starting in 1968, Republicans won eight of 13 presidential elections, controlled Congress for protracted intervals after spending most of the preceding four decades in the minority and appointed 15 of 19 Supreme Court justices. Published in 2001, “Before the Storm” recounted the rise of the firebrand Goldwater as the progenitor of this movement. Perlstein’s next two books, “Nixonland” and “The Invisible Bridge,” encompassed Richard Nixon’s presidency, followed by Ronald Reagan’s emergence as Goldwater’s heir. “Reaganland: America’s Right Turn 1976-1980” concludes Perlstein’s authoritative and engaging series with Reagan capturing the White House.

Initially considered too conservative to win a national election, Reagan benefited from the electorate’s shift to the right, the development of unrivaled grass-roots and fundraising networks, and the exploits of cutting-edge political operators.

Perhaps no group personified these developments better than the New Right. Described by one of its pioneers as “radicals working to overturn the present power structure,” these public relations experts and campaign strategists commonly operated without the GOP’s imprimatur. Brazenly exploiting legal loopholes and shattering norms to the chagrin of the party’s patricians, the New Right zeroed in on racial resentment and divisive social issues — abortion, gay rights and the Equal Rights Amendment — to stir voters’ emotions. “We organize discontent,” declared one of its leaders, Howard Phillips. Alarmist and ugly — one newsletter opposing homosexuals and gay rights vowed to “protect . . . children from their evil influence” — the strategy nevertheless corralled Reagan Democrats to the party.

As the New Right mastered these newfangled strategies, religious institutions and large businesses, which had intermittently dabbled in partisan politics in the 1960s, gelled into strongholds for the GOP. Led by Jerry Falwell’s Moral Majority, evangelicals abandoned Jimmy Carter over abortion and gay rights and, through the proliferation of Christian television stations and direct-mail operations, backed Reagan even though he, like Donald Trump, had been divorced and was not particularly devout. Wary of escalating environmental and consumer protection regulations, corporations — “boardroom Jacobins” in Perlstein’s lexicon — amped up their lobbying efforts to promote the GOP’s calls for deregulation and lower taxes.

While Reagan is the book’s central figure, Perlstein chronicles this transformation through the exploits of culture war trailblazers and political advisers such as Phyllis Schlafly, Richard Viguerie and Anita Bryant who led the GOP’s about-face on the ERA, voting rights and the Panama Canal treaty. Perlstein’s knack for bringing these long-forgotten clashes to life and his eye for telling details — along with cameo appearances by Roger Stone, Paul Manafort and Trump, a “hungry young killer” out to conquer New York real estate — conjure many eye-opening moments. Although Perlstein rarely draws explicit comparisons to modern-day politics, the unnerving parallels between the time periods — and the origins of the many divisions currently ailing the nation — jump off nearly every page. Reading “Reaganland,” it’s easy to identify Trump’s imitation of the New Right’s ploys and its fixation on toxic, socially contentious issues to woo voters through emotional appeals.

The era continues to resonate in other ways as well. The New Right’s purging of Republican moderates and ousting of Democrats from states with small, conservative populations accelerated a trend started a decade earlier. This expulsion of centrists from the political landscape and the reduction of ideological diversity within the parties fueled hyper-partisanship for decades to come. Lacking the bountiful incisive commentary of Perlstein’s earlier work, however, and bogged down by the unremitting rotation between multiple story lines, “Reaganland’s” narrative doesn’t reach full speed until the 1980 campaign.

Conservatives were fortunate to have Reagan serve as the prophet delivering their radical message. Though he, too, strove to steer the party away from the “country club big business image” epitomized by Nelson Rockefeller, Reagan never projected a cutthroat persona, earning the public’s affection over Carter, who came off as increasingly coldhearted. Reagan’s biggest handicap was his tendency to blurt mistakes and falsehoods — one commentator said he had a “very loose hold on the real world around him” — when going off-script. Critics pounced on his gaffes questioning evolution and asserting that vegetation caused pollution, but, as with Trump, Reagan’s backers cared little about these blunders or his nescience over public affairs. His telegenic charisma, unapologetic patriotism (“Make America great again” became a campaign slogan) and sanguine vision overwhelmed an incumbent prone to scolding the public for its profligate ways. Unable to lift the nation’s spirits, Carter’s “Scrooge” was no match for Reagan’s “Santa Claus.”

These forces alone didn’t explain Reagan’s triumph. Blinded by overconfidence and mired in internecine divisions, liberals had no response to conservatism’s subterranean growth. Lacking a cohesive vision, Democrats failed to refashion the formidable coalition of labor unions, religious organizations and civil rights groups from the 1960s. A testy relationship between Carter and congressional Democrats, compounded by his bruising nomination fight with Ted Kennedy, squandered the opportunity to leverage the party’s gains after Watergate. It’s no wonder that Democrats suffered their worst drubbing in more than a half-century.

Over time, liberals learned to counteract the right’s stratagems, but even Bill Clinton and Barack Obama — the two savviest Democratic leaders of the past six decades — failed to unite the party’s fragmented factions or forge a cogent and lasting doctrine. Clinton, in particular, outmaneuvered his archrival, Newt Gingrich, yet shifted the party firmly to the right to prevail. In doing so, he defined the Democrats on Republican terms.

In many ways, the right wing’s ascent that Perlstein has admirably recounted owes as much to avant-garde tactics, the passion of its adherents and the changing tastes of the electorate as it does to the inability of Democrats to effectively and consistently confront conservatism with a vibrant, clear and enduring alternative. The complete story of conservatism’s rise during the past 60 years cannot be told without accounting for liberalism’s role in its ascension.

Reaganland

America’s Right Turn 1976-1980

By Rick Perlstein

Simon & Schuster. 1107 pp. $40