A Closer Look at Trump's 'Coattails Effect'

This year looks a bit more like a Republican wave in which the nominee was the last ashore.

Who owes whom?

Photographer: Justin Merriman/Getty Images

During the presidential campaign, it was commonly said by analysts on the left and the right that any other Republican nominee would be beating Hillary Clinton handily. (Well, maybe any other Republican except for Ben Carson.) That piece of conventional wisdom should have been a clue that those analysts were underestimating Donald Trump’s chances: If anyone else would have beaten her, it meant that she was a very weak candidate; and if she was so weak, maybe he would beat her, too.

The actual results suggest that this pre-election mantra was wrong: that other Republicans wouldn’t have beaten her as soundly in the Electoral College as Trump did. A more conventional Republican candidate than Trump -- say, Marco Rubio or John Kasich -- would probably have won more white voters with college degrees and fewer white voters without those degrees. (Trump’s numbers were lower than Mitt Romney’s in 2012 in the first group and higher in the second.)

That trade might have helped Republicans in the popular vote, and maybe given them New Hampshire’s 4 electors. If a Kasich or Rubio had made gains among Hispanics, maybe Nevada’s 6 and Colorado's 9, too. But without Trump’s huge margin among whites without college degrees, the Republicans would not have won the 46 votes in Michigan, Pennsylvania and Wisconsin. They might not have won Iowa’s 6 votes either.

Considering what might have happened with a different Republican nominee may help illuminate the post-election debate about whether Trump had “coattails” in the Senate. Trump campaign manager Kellyanne Conway says Trump’s performance helped Republican Senate candidates, and others have noted the defeats of some Republican Senate candidates who turned on Trump: Kelly Ayotte in New Hampshire, Joe Heck in Nevada and Mark Kirk in Illinois.

Those three examples don’t tell us much. For one thing, John McCain in Arizona and Rob Portman in Ohio rejected Trump and won big. For another, each of those defeated candidates ended up running ahead of Trump in their states. And their repudiation of Trump probably had something to do with the fact that they thought Trump would lose their states -- as he did.

The Republicans who turned on Trump were not a random sample of Senate candidates. One winner, Pat Toomey of Pennsylvania, barely embraced Trump, saying he had voted for him at the end of voting on Election Day. He also ran ahead of Trump.

Senate candidates ran ahead of Trump in four other competitive states, too. Trump ran ahead of the Senate candidates in a few states: Alaska, Colorado, Indiana and Missouri. It was a marked contrast to 2012, when Romney ran ahead of Republican Senate candidates in 24 states. 1

In 2012, it looked like the party was dragging down a presidential nominee who was more popular than most of its politicians. This year looks a bit more like a Republican wave in which the nominee was the last ashore.

To evaluate the coattails question, though, requires looking at the interaction of demographics and geography. The Senate elections were highly correlated with the presidential one: Republicans didn’t win a competitive Senate seat in a state Trump lost, and didn’t lose one in a state he carried.

Should the Republican Senate candidates be grateful that Trump did as well as he did? Yes: If he had done worse they would likely have done worse too. Do some Senate Republicans owe their elections to the fact that Trump rather than someone else won the nomination? Probably: You can make a case that two or three senators would have lost with a nominee who appealed less to the white working class. (Joe Heck in Nevada and Kelly Ayotte in New Hampshire, on the other hand, might have won their races with a different nominee.)

One more question: Does it matter whether Trump helped or hurt his party’s Senate candidates? Probably not. Romney was pegged as a loser in many Republican circles, even though he ran ahead of most Senate candidates, and Trump will go down as a winner even though he ran behind -- and appears to have gotten a lower percentage of the total vote than Romney.

In politics as elsewhere, there’s nothing quite like winning. 

This column does not necessarily reflect the opinion of the editorial board or Bloomberg LP and its owners.
  1. I can think of two ways this comparison may understate Trump’s strength. The first is that most of the 2016 Senate races did not feature significant third-party candidates while the presidential race did. We would therefore expect Trump to do a bit worse than Republican Senate candidates, on average. But if we are judging the political appeal of Trump compared with Republican Senate candidates, the point does not matter: After all, it was the unpopularity of both Trump and Clinton that made the third-party candidates in their race significant. The second issue is that the Republican candidates for Senate in 2016 were more likely to be incumbents, which should have helped them.

To contact the author of this story:
Ramesh Ponnuru at

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Katy Roberts at

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