PITTSBURGH (AP) — Hearing chants of “Run Joe, run,” President Joe Biden marched in Pittsburgh’s annual Labor Day parade on Monday as speculation swirled about a potential late entry into the Democratic presidential campaign.The vice president donned a black-and-gold United Steelworkers union hat and told hundreds of union members that the gap between the wealthy and poor was hurting the nation.“The tax code’s not fair. It’s simply not fair,” Biden said in a city long associated with organized labor. “The wealthy aren’t paying their fair share.