Mine is that he was buddies with communists... much like Horowitz in his youth. Got disenchanted for some reason or another... and became a simple rabble-rouser... a sawed-off hothead with no affiliations.
The difference between Weiner and Horowitz is that David knows American history... Weiner just tells you that he does.
He was right a long long time ago. It was all about borders culture and language. Others stole his mantra and he got all the crazier and crazier as time went on.