The scenario for Republicans would be akin to 1974. Thanks to Watergate that year, Republicans were wiped out across the board, even though President Ford was reasonably popular. Democrats gained 49 seats, inflating their numbers to 291, roughly the levels found in the Great Society/New Deal congresses.
It wasnt that the country suddenly discovered an affinity for Democrats. Democrats received only 970,000 more votes than they had received in the previous midterm election of 1970. But Republicans hemorrhaged over 3 million votes. In other words, people didnt flip their votes so much as a demoralized and disgusted GOP base opted to stay home.
Take Indiana. The Hoosier State was swingier back in those days, and Republicans entered the election holding seven of the states 11 seats. After the dust cleared in 1974, they found their numbers reduced to just two.
Some of the Democrats pickups were predictable, such as Andrew Jacobs winning back the seat that he had lost in the 1972 Nixon landslide, or Earl Landgrebe, who had won a fluky 11-way election in 1968, succumbing to the wave. Others were not. Consider William Bray, who had been elected to the House in 1950, and represented a district that had given Richard Nixon 74 percent of the vote. His opponent only increased the Democratic vote total by 3,815 votes from 1970. But Brays vote total collapsed by 43,979 as Republican base voters stayed home. He lost.
Another example was Rep. David Dennis, who had been one of Nixons strongest supporters on the House Judiciary Committee. In a district that Nixon had carried with 55 percent of the vote in 1968, Dennis loyalty seemed like a safe bet. It wasnt. Phillip Sharp increased the Democratic vote total by 6,547, but Dennis declined by 9,738. He lost.
Not all districts followed this pattern, but the general outcome was that the Republican vote share declined in some heavily Republican districts, and there were many losses in districts previously thought to be safe for their party.