“Joe Biden leads 2020 Democrats in millennial support, poll finds,” reads a CBS News article.
The article lists a survey from GenForward, a project of the University of Chicago.
I went and found the underlying survey, and there’s an important caveat here. The polling that shows former VP Joe Biden as ranked above Vermont Independent Senator Bernie Sanders is segregated into two slides, one of which is general millennials, and the other is several categories of Democratic voters. You can see there is a significant difference:
A fairly small number of people vote in Democratic Party presidential primaries, and they tend to be people who affiliate with the Democrats. This is an important asterisk on this poll, which suggests that Biden may not be trouncing Sanders among millenials after all.