The addition of SEIU members would bring the total number of AFL-CIO members to nearly 15 million, helping increase the political heft of a federation already composed of 60 unions.

Less than two weeks before President-elect Donald Trump takes office for his second term, two major unions have announced they will reunite to “push back on union-busting and win for working-class families.

Both AFL-CIO President Liz Shuler and SEIU President April Verrett were careful to say in interviews Wednesday that the combination was not a consequence of Republican Donald Trump winning the ...