As 10 Democrats fight for talking time during tonight's Detroit debate, there's a burning question distracting some viewers: What's going on with Pete Buttigieg's forehead? The South Bend, Indiana mayor showed up at Tuesday's Democratic presidential debate with a smudge on his forehead that didn't go unnoticed online. Wit hair dye? Lint? A bug? Whatever it was, the smudge was gone by about 9:20 p.m. Twitter users held debates of their own trying to solve the mystery. And finally ... Live fact check: Democratic debate in Detroit, Day 1