They promote em until they are horrible enough to be a danger to losing the power for the Dems.
We've know all about those assholes and it didn't mean dick to them til then. Especially Swalwell. imgflip.com/i/aoxhoe
Remember: Both of these men were vetted by the DNC and put forward to run for, and hold elected office. Democrats promote people like these two until voters find out who they really are