However, by the same token, it is wrong to say that the prolife position HURTS a politician -— that only happens if the candidate can be painted as “single issue” and not up to speed, on other issues.
You are pretty much dead on with most of that.
I would augment the last part by including a politician who puts an emphasis on opposing abortion at all in a pro-abortion state like California.
Voters don’t care if it isn’t made an issue, however, there is one thing you’re overlooking, at least with Feinstein and Boxer’s campaigns here in California: THEY make it an issue. Every time. It is their main issue in every election. Usually their ONLY issue. Every ad (and they run them statewide) focuses on their support for abortion, and they always prominently attack the Republican for opposing it. And they win every election. their opponents never get off the ground floor here.
I really don’t think either Boxer or Feinstein can be defeated unless the GOP runs a pro-choice candidate. Not so much because it’s a winning issue here (though it is) but because Feinstein and Boxer in particular wouldn’t have anything to run on if they didn’t have the “my opponent is a scary Republican who will take away your right to an abortion” card to play. Instead their actual records would get some scrutiny, and they would suddenly become very vulnerable.