kfb: An endorsement of a candidate does not mean a support of all of their policies. It means you think that, overall, they are the best candidate.
And even though R’ Moshe held a Davar Pashut that abortions were murder, a majority of Achronim and contemporary Poskim held not so. It’s Assur, certainly, but calling it “killing babies” is Pashtus not so accurate.