Reagan had the support of the Teamsters as he went into the election in 1980. Jimmy Carter was just too far left; his energy policies were killing their members and therefore their dues.
So far, the glitter of AOC and gang is irresistible to the D party but they will have to do something about this schism. Will they will make an obamacare-type arrangement like exempting industries they care about? Kamala could reassure them that she would take care of them if she were potus.