Joe Biden’s victories on Super Tuesday illustrated the importance of campaign momentum. He won in several states where he had little to no campaign infrastructure and did not advertise. That was possible because of his commanding support from African Americans and older voters.

Also, Mike Bloomberg exits the race and Elizabeth Warren considers her future.

This episode: congressional correspondent Kelsey Snell, demographics and culture reporter Juana Summers, and senior political editor/correspondent Domenico Montanaro.