Lyndon Johnson’s 1964 election landslide, big Democratic gains in Congress, and the subsequent flood of liberal legislation flowing from Washington persuaded many observers that the Republican Party was nearly defunct. At best, they reasoned, it would take years for the GOP to reconstitute itself and regain relevance in the American system.

Two years later, Republicans were revivified and on the brink of an era of increasing political success, including near-domination of presidential elections that Democrats have occasionally overcome but have not yet ended four decades later.

A number of events took a toll on Johnson’s popularity by late 1966, including lack of demonstrable success in Vietnam, race riots and other civil disturbances at home, and an increasing sense that the Great Society was running amok, spending too much and centralizing too much.

When all was said and done, the GOP gained 47 House seats, three Senate seats, eight governorships, and 557 state legislative seats. Republican governors controlled 25 states, the most since the early 1950s. Republicans actually won a majority of the aggregated national vote for U.S. Senate. Of the 38 House districts where Democrats had replaced Republicans in 1964, only 14 remained in Democratic hands in 1966.

The 1966 elections had a number of important effects:

• Lyndon Johnson’s legislative momentum was halted entirely. He proposed few new initiatives in 1967, and saw anti-poverty budgets cut. As Newsweek put it, "in the space of a single autumn day… the 1,000 day reign of Lyndon I came to an end: The Emperor of American politics became just a President again."

• By all accounts, Republicans immediately gained a huge psychological boost as they contemplated their prospects for 1968 and beyond. Journalists Stephen Hess and David Broder contended that improved expectations had "altered the whole psychological climate of internal Republican politics."

• The bolstered GOP contingent in Congress was able to put forward new policy ideas that were later picked up on by Richard Nixon in 1968 and beyond, especially proposals for enhancing federalism.

• Republicans were able both to regain strength in their Midwest bastion and to make serious inroads in Congress and governorships in the South for the first time since Reconstruction. Indeed, 1966 was a breakthrough year for the GOP in the House, as it picked up about one-third of Southern House seats. That ratio would remain constant until the next big surge in 1994.

• A surfeit of Republican leaders were advanced. Indeed, all four of the men who were elected Republican presidents between 1969 and the present owed much to 1966. Richard Nixon campaigned hard for GOP candidates, correctly predicted the result, and later said that 1966 was a crucial step on his road to the White House. Ronald Reagan was elected governor of California in 1966, and immediately became a national conservative leader. George H.W. Bush began his elective career, winning a seat in the U.S. House in Texas in 1966. And without a President George H.W. Bush, there would probably not be a President George W. Bush.

Altogether, Republicans reaped huge benefits from the 1966 elections. It is no exaggeration to say that the Great Society era of federal policymaking ended with the elections of 1966, or that the modern era of Republican strength began in 1966. Republicans would win seven out of the next ten presidential elections, starting with Nixon two years later.

Andrew E. Busch is a Professor of Government at Claremont McKenna College and an Adjunct Fellow of the Ashbrook Center.