Former Vice President Joe Biden, the frontrunner for the 2020 Democratic presidential nomination, told a Detroit union auto-worker on Tuesday as Michiganders went to the polls that the worker was "full of shit" and threatened to fight him.

"You want to go outside with me?" Biden asked the auto-worker during a tense exchange on gun rights in which the former vice president referred to "AR-14s" and asked why anyone would need "100 rounds" in a machine gun.

Watch:

WATCH: "You’re full of sh*t," @JoeBiden tells a man who accused him of "actively trying to end our Second Amendment right."



"I support the Second Amendment," Biden adds while vising under-construction auto plant in Detroit. @CBSNews pic.twitter.com/sueOSBaY9P SCROLL TO CONTINUE WITH CONTENT Never Miss a Beat. Get our best delivered to your inbox.





— Bo Erickson CBS (@BoKnowsNews) March 10, 2020

The auto-worker referenced comments he claimed Biden made in a "viral video" that he watched, but it was not exactly clear what he might be referring to.