It would be no different if someone was voting for a horrible candidate simply because they are pro-life. If they are horrible on EVERYTHING ELSE, there are still plenty of one-issue voters who would vote for a politician simply because they are pro-life, despite being wrong on EVERYTHING else.
That's what the woman you cited is doing. And one-issue voting is ALWAYS irrational and a bad idea.
BagCamAddict, I am much more of a fiscal conservative because our nations economy is in dire straits. Social issues will be controlled by appointing conservative judges and via the family imho