A spate of labor-related election postmortems converged on one key theme: Donald Trump managed to cleave significant union support away from the Democrats. …. It is true that the Democratic-Republican vote split among union households was narrower in 2016 than in any time since, well, Ronald Reagan’s re-election. In 2016, exit polls indicate that voters in union households supported the Democratic over the Republican candidate by only 8 points. In 2012, by contrast, the Democratic advantage among members of union households was a yawning 18 points. And 2016’s gap looks positively miniscule compared to the Democratic vote advantage among union households Bill Clinton enjoyed. In 1992, exit polls suggest that members of union households preferred Clinton to George H.W. Bush by over 30 points. ….
…. But there is another way of investigating the issue. What if the shrunken Democratic vote advantage among union households in 2016 didn’t so much stem from Trump’s inroads among union household members, but from union households turning to outsider candidates over the Democratic Party choice? ….