As Jews, we don’t see our vote as that significant on the national scale. The number of Jews in the US is less than the population of Massachusetts.
If I am running for office, and I know that a group will usually vote for my party or against my party 9 times out of 10 no matter what I say or do, then I will take for granted that a certain number of votes are either coming my way or going to my opponent. Our mistake is to hand the Dems a blank check without getting much in return.
I don’t think that people expect “moral leadership” from goyish politicians. We have our rebbeim, and we don’t expect a politician to be cut from the same cloth.