Shawn Fain has ushered in a more militant union, but critics question how he has wielded his power. As Shawn Fain seeks another term as president of the United Auto Workers, he has plenty to stake a campaign on. Defined by his effusive profanity and "Eat The Rich" T-shirts, Fain steered a union once known for cordial handshakes with auto executives in a more militant direction.

He has led strikes on the three Detroit automakers and become a prominent voice in the wider labor movement. Now, Fain's path to re-election is complicated by a credible challenge from a UAW vice president who was once an ally.

Meanwhile, a court-appointed monitor for the union has accused Fain of dishonesty and underhanded management tactics. Some of the allegations led to the resignation of Fain's chief of staff. Then last month, the monitor claimed Fain abused his power to benefit his fiancée. The Justice Department is now probing that allegation.