Joe Biden is escalating his criticism of Democratic presidential rival Pete Buttigieg. Biden is mocking Buttigieg's experience as mayor of South Bend, Indiana.
And he's warning that Buttigieg would struggle without the support of black voters who are the backbone of the Democratic Party.
The former vice president says he believes the party would be at risk if it nominates someone who's never held a higher office than South Bend mayor.
Biden is hoping to avoid falling further behind Buttigieg and Vermont Sen. Bernie Sanders.
Those two candidates nearly tied in the Iowa caucuses last Monday in what was the first contest on the election calendar.
