And, for the record, as a Jew, I ordinarily eschew Holocaust comparisons, because I believe that every genocide should be treated sui generis.
So I don't believe Donald Trump should be compared to Hitler. Trump's lust for power is more narcissistic than anything else, and the danger is more that Trump will capitulate to Putin than that Trump will rule the US with an iron fist. Therefore, Trump is comparable to Benito Mussolini, but not Hitler.
Nevertheless, I think every Jew has a moral obligation to oppose Trump, in every way possible, for the reasons outlined by Rabbi Jill Jacobs in this Washington Post op-ed:
WASHINGTON POST: Why Jews have a special obligation to resist Trump
"Even if Jews were not personally threatened as Jews, it would still be imperative for us to call upon all of the communal strength we have and all of the institutions we have fought to create to oppose threats to other people. This is an obligation that comes from our tradition. In the Torah, one of God’s first commands to the Jewish people after our liberation from slavery is to protect those who are most vulnerable, as we, too, know the experience of being strangers.
Our history has taught us that autocracy does not arrive all at once, but through the slow erosion of individual liberties and the pitting of one group against another. We cannot look away or hope for the best when politicians promise to assault our civil liberties and threaten human rights."