… Despite years of pummeling by Republican-controlled legislatures that have sought to weaken their power, unions are still viewed by Democrats as an important constituency: A Gallup poll conducted in August found that 82 percent of Democrats approve of unions. And beyond the seal of validation endorsements afford, union members still play a critical role in canvassing voters and mustering them to the polls.
Though union members have traditionally voted Democratic, many are also eager to hear a candidate address their grievances, a desire that President Trump was able to harness in 2016, presenting new challenges for candidates courting endorsements. Hillary Clinton beat Mr. Trump by only nine percentage points among voters from union households, according to exit polls, a smaller margin than the 18-point advantage President Barack Obama had over Mitt Romney in the 2012 election. CONT.
Sydney Ember & Thomas Kaplan, New York Times