I haven't really talked to him about Israel. His mother is somewhat critical of Israel. As far as immigration I sent him an article years ago about democrats importing voters and he just said the data wasn't accurate and he essentially expressed the nation of immigrants argument. I didn't really feel like arguing with him about it at the time but if we hang out again I probably will broach these topics with him.

Also curious whether he married a Jewish girl.

He did. His wife is also even more liberal than he is.

From my experience many of them become more Jewish the older they get, probably in part because of the career and social benefits they can tap into from being active Jews

I'm seeing this as well. When my friend was young his family wanted him to 'blend' in. Now they are totally fine that he's staunchly liberal. He does have the capacity to reason and play with logic during conversations but he has this weird conversational style where he just acts like anyone that disagrees with him is just stupid and doesn't read enough and doesn't know as much as him ( a little like Sam Harris). He really didn't have this before college. He was very balanced. I'm not sure what really triggered this new identity but I suspicion it has a lot to do with becoming an urban hipster and hanging out with a lot of people that echo themselves into more and more radical views.