As I've posted here before, due to the geographic distribution of the diverse segments of the Jewish community, it is extremely difficult, tedious, inefficient, and time-consuming to come up with and implement a strategy calculated to get an accurate estimate of the true national Jewish vote.
You mentioned Brighton Beach, Brooklyn, which is an area dominated by relatively recent Russian Jewish immigrants and their descendants, a subset of the Jewish population which undoubtedly will vote overwhelmingly GOP for president this year. But you can be assured that just about every pollster trying to estimate the "Jewish vote" will undercount or underweigh this subset in their sampling, largely because of language and social and cultural barriers. These people, because of their recent history in the USSR, will be relatively unlikely to be forthcoming with pollsters or even to participate as a polling interviewee at all.