By Nandita Bose and Jarrett Renshaw WASHINGTON (Reuters) - President Joe Biden will address union members in Philadelphia on Saturday in his first political rally since announcing his re-election campaign, aiming to shore up a key part of his political coalition and bolster support among white working-class voters. The AFL-CIO, which includes 60 unions representing more than 12.5 million workers, endorsed Biden and Vice President Kamala Harris on Friday, the earliest it has ever endorsed in a presidential election, and is hosting Saturday's event. Biden's frequent appearances at union events, ...
