Is Joe Biden Running For President? His Labor Day Speech Is Telling

In what may turn out to be an audition for yet another presidential bid, Vice President Joe Biden delivered a rousing Labor Day speech on Monday before a Labor Day march in Pittsburgh. The vice president has been heeding calls by many Democrats to launch a presidential campaign, which would provide fresh challenges for current presidential hopefuls Hillary Clinton and Sen. Bernie Sanders. While Biden has yet to toss his hat in the ring, Monday's fiery speech touched upon the potential prevailing theme of the Democrat's 2016 campaign — that progressive reforms can boost a floundering working- and middle-class economy — signaling that Biden is perhaps warming up to the idea of a third presidential bid.

Speaking to thousands there to march in support of the trade union AFL-CIO and workers' rights, Biden attacked current policies that have "clobbered" American workers, including those protected by once-powerful unions. Building upon the rhetoric of progressive Democrats such as Sanders and Sen. Elizabeth Warren (D-Mass.), the vice president honed in on America's growing economic inequality.

"It used to be when productivity went up in America, everybody got to share," Biden said. "The people who caused the productivity increase, they got to share. They got a piece of the action. Something is wrong, folks."

The vice president played up the value of labor unions — understandably, considering Labor Day was founded by the American labor movement. But Biden's words were in stark contrast to Republican presidential hopefuls like Jeb Bush and Wisconsin Gov. Scott Walker, the latter of whom is notoriously anti-union and collective bargaining.

"You built the middle class," Biden continued. "That’s not an exaggeration. And as you’ve declined, the middle class has declined. ... Build labor, we build America. Build labor, we build the middle class."

The vice president also played up some other progressive 2016 talking points in his speech, including free community college and affordable higher education — a platform issue that has attracted young voters burdened by student debt to Sanders.

While Biden has said recently that he may not have the "emotional energy" to go after the Democratic presidential nomination, the vice president is seeing growing support among voters, who've appeared to become more disenchanted with Clinton. An NBC News/Marist poll released Sunday showed that Biden already has 16 percent of voter support in New Hampshire. The poll also revealed that Sanders had overtaken Clinton, receiving 41 percent of Democrat's support; Clinton came in at 32 percent.

According to another NBC News/Marist poll released Sunday, 20 percent of Iowa Democratic voters said they would support Biden. That figure puts him just slightly below Sanders, who received 27 percent of support in Iowa.