Union Workers Weren’t a Lock for Biden. Here’s Why That Matters

Union votes helped President-elect Joe Biden win the crucial swing states of Michigan and Wisconsin, but a majority of union households backed President Donald Trump in Ohio and Pennsylvania—raising questions about how Biden can use policy to shore up Democrats’ “Blue Wall.”

Biden won 57% of union households nationwide compared with 40% for Trump, according to Edison Research, which produces exit polling for major news organizations. That was double Hillary Clinton’s eight-point edge with union households in 2016.

In the 2020 election, where polling writ large has been widely criticized for inaccuracies—and Trump is still contesting the outcome—any conclusions that ...