I do not like seeing Catholics (or Americans) choose sides against each other. It never turns out well. While I am not a single-issue voter by any means, I understand why some are, and would encourage all to respect that choice. Abortion is really, really, bad. It is unique, evil, singular, and deserving of single issue voters. I only would encourage those who take this issue as the sole determiner of who they vote for to respect those who do not. It should be enough that the Church’s understanding of life permeate our faith. Then trust your fellow Catholics. If we were all single issue voters, then politicians would have no reason to ever listen to Catholics, except on one issue. If we had no single issue voters on abortion, then there would be no political reason for a politician to be against it.
The Republicans deserve to have some Catholics abandon their candidate, considering their choice last election, just like Democrats deserve to have Catholics consider them the party of death. There is room for more than one Catholic opinion. While in any given election it may look counterproductive, there are strategic goals that go beyond a single election cycle.