Honestly, at this point it might be Jared Kushner, Ivanka Trump and Chelsea Clinton.
The Jewish Democrats in elected office are getting older. Al Franken could be a credible candidate, but we haven't seen much interest, and there are more prominent faces in the party.
Due to the lack of prominent obvious Jewish officeholders at the moment, it's probably not going to be someone in 2020 or 2024. When we get to later elections, those may very well involve people who aren't currently in major elected office.)
Chelsea Clinton is a Methodist