Trump’s performance was targeted to the Bernie bros, not the general public. Many will abandon Biden now.
Definitely the young Bernie voters will probably stay home. That’s why the Dems are planning the massive vote by mail fraud. They know they will not be able to get their voters to turn out so they have to fraudulently inject enough mail in ballots to put their crook over the top.
The die hard Bernie supporters will still vote for Biden, though. They don’t care what he says in the debates. They know he can be controlled and they are just trying to get him elected so that they can take over.