In some unions, especially the building trades, support for the
president remains solid despite the efforts of labor leaders to
convince members otherwise.
by Holly Otterbein and Megan Cassella, POLITICO, Sept. 22
https://www.politico.com/news/2020/09/22/donald-trump-union-support-snub-joe-biden-418329?fbclid

"Joe Biden has pitched himself to voters as a “union man,” a son of
Scranton, Pa., who respects the dignity of work and will defend
organized labor if he wins the White House.

Reagan Democrats.