David Schraub has a nuanced view of Glenn Greenwald's decision to write for The American Conservative:
I cannot think of a conversation that has this extreme a ratio of heat to light. I think most American Jews have a definitively negative view of The American Conservative, because Buchanan-style conservatism has always been extremely unpopular with American Jews and most Jews do consider him to be flatly anti-Semitic. Greenwald's writing in that magazine was, at the very least, probably a tactical mistake regardless of the content, if the goal is to persuade the Jewish community writ large that the dovish positions that Greenwald holds are a safe location for them. But I don't think he himself is anti-Semitic or that there are any grounds to imply otherwise.