PITTSBURGH -- Hearing chants of "run Joe, run," Vice 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. There used to be one America."
Biden later walked along the city's downtown with a large contingent of steel workers, hearing encouraging words along the parade route.
"Give it a go, Joe!" shouted one woman.
Biden is seriously considering a late entry into the 2016 Democratic presidential campaign. His entry could jumble a Democratic contest that has seen front-runner Hillary Rodham Clinton's lead diminish in early states against Vermont Sen. Bernie Sanders, an independent who describes himself as a democratic socialist.
Underscoring the volatile nature of the race, an NBC News poll released Sunday showed Sanders gaining an advantage over Clinton in New Hampshire, a state where Bill and Hillary Clinton have maintained deep ties during their political careers.
Biden, however, said last week he wasn't certain if he and his family had the "emotional energy" for another campaign.
But the campaign was clearly on the minds of his audience. During a speech before a few hundred steelworkers, Biden said the media liked to portray him as a populist. "They'll probably say (I'm) competing with Bernie Sanders, who is doing a helluva job by the way."
When one man shouted that Biden should run for president, the vice president responded, "You gotta talk to my wife about that. I gotta talk to my wife about that." His wife, Jill Biden, is said to share some of her husband's misgivings about whether the family should pursue another presidential bid following the death of their 46-year-old son, Beau Biden.
AFL-CIO President Richard Trumka, who joined Biden at the parade, said the vice president got a strong response from the city's workers.
"If you're looking for energy, this is a great place to get energy today," the labor leader said.
Clinton also sought union support on Labor Day during stops in Iowa and Illinois, vowing to fight for collective bargaining rights and to protect pension benefits and Social Security.
"We're going to make it harder and harder to stop what should be the right of every American to join a union," said Clinton, who was endorsed by Rep. Dave Loebsack, an Iowa Democrat.
Associated Press writer Catherine Lucey in Hampton, Illinois, contributed to this report.
'Give it a go, Joe': Pittsburgh union crowd cheers on Biden