When you decide if he gets your critical support, the transphobia accusation is 100% legit.
But the stuff I hear about him not being socialist, grifting, opportunism... the man has held the same positions on Western Imperialism and worker's rights consistently since the 70s. Demonstrably so. Loudly so.
I found a YouTube link in your post. Here are links to the same video on alternative frontends that protect your privacy: