In Defying the Odds, we write:
Was Trump responsible for the Republican victory? It is possible that he helped the GOP by spurring turnout in key states, but it is unlikely that he deserves the main credit. He lost the aggregated popular tally nationwide, and his share of the vote was generally smaller than that of Republican Senate candidates. Table 5.2 displays the results for the ten states that RealClearPolitics listed as “tossups” or “leans.” Only in Indiana and Missouri did Trump get a greater share of the vote than the GOP winner. In Nevada, he won a larger percentage than Heck, but both lost the state.At The Hill, Reid Wilson writes of Pat Toomey (R-PA) and Ron Johnson (R-WI):
The two incumbents triumphed and Republicans retained their narrow Senate majority because of the occasional voter who showed up to cast a ballot for Trump, but also because of “Never Trump” voters. This group leans Republican in any given election, but they could not bring themselves to cast a ballot for the party’s brash presidential nominee.
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In Pennsylvania, Toomey won reelection by 84,000 votes, while Trump carried the state by 44,000.
Democrats typically run up the score in the Philadelphia area, and both Clinton and Toomey’s opponent, Katie McGinty, followed the same playbook. Clinton beat Trump in those eight counties by a combined 647,000 votes. But McGinty beat Toomey in those counties by just 456,000 votes, a difference of 190,000 votes — more than twice Toomey’s statewide margin of victory.
Toomey outperformed Trump in Philadelphia and in the four collar counties that surround the city. McGinty received fewer votes than Clinton did in all eight counties that make up the Philadelphia media market.
In Wisconsin, Johnson won by a margin of 99,000 votes, while Trump carried the state by just 23,000. Like Toomey, Johnson overperformed Trump in the state’s most populous region: He won more votes than Trump did in all 10 counties that make up the Milwaukee market.