But Zev Chafetz does a good job at giving a longer answer.
The short answer, as I have written before is that most of these individuals are liberals who have just been born Jewish. Their religion is actually liberalism-not Judaism, not matter what they say with a Yiddish accent and how many bagels they eat.
He says:
"The fact is, the great majority of American Jewish Democrats see their
party and its agenda as their secular religion. Reform Judaism,
America’s largest Jewish denomination, is sometimes jokingly called “the
Democratic Party with holidays.” A lot of Jews would sooner convert to
Shia Islam than leave the party of their forefathers."
"Jews of all sorts tend to be pro-Israel. For many it is personal. But
that doesn't mean supporting specific policies. The Democrats will
retain their loyalty as long as the party maintains an acceptable level
of support for Israel – to be, as Barack Obama once said about Hillary
Clinton in a different context, “likable enough".
But, given Obama's outright disdain for Israel and Jews, it is even more disgusting for Jews to support the Democrats. Obama "likeable enough"? Give me a break.
Clearly-this shows their loyalty is for liberalism first, and anything Jewish and all things Israel far, far down the list.
Liberalism is definitely their religion.