CPUSA always endorses the Democratic klanidate so that's not exactly news. Our brave men, women, and gender nonconforming persons in the FBI believe in the party of good governance.
I read Chairman Bob's endorsement so you don't have to, in short: Trump is a fascist (Dog Mod vindicated) and defeating him is an "immediate, urgent question and truly historic imperative."
Setting that aside (and the fact that we're comparing a line organization commonly described as a cult to an incoherent federation) RCP has much more of a minority membership than DSA, I suspect on par with PSL. A lot of Chairman Bob's endorsement listed Trump's litany of wrongdoings against minorities, both citizen and subject. DSA is (in)famously a very white organization.
DSA also went all in on the Bernie campaign (which was not an uncontroversial policy decision at the time) and counterintuitively can have a strong ultra-leftist bent in its membership. On Earth-2 the often but unfairly mocked brake light clinics put on by locals served as the nucleus of mutual aid organizations that filled the vacuum left by the U.S. government abandoning its obligations during the COVID-19 portion of 2020.
