DS (18) is an American citizen and Catholic and is inclined to support Ron Paul in general; we have had many a discussion of how Paul's ideas are a load of hooey and predicated on the vital condition of a terrific rate of growth in the economy, sustained indefinitely. I think Ron Paul appeals to a lot of young people who haven't really examined their assumptions, especially young American men, because the self determination and rugged individualism philosophy that informs so much of American culture and ethos, and Ron Paul's platform, were basically dreamed up by and operate in favour of young men who have, through little effort of their own perhaps, arrived at a point in their lives when they can see themselves making it/fulfilling the 'American dream'. It's an intellectual trap many Americans never get out of.
Now that the individualism has been harnessed to the religious fundamentalist wagon I anticipate a wild ride downhill with much yeehawing, and a crash at the bottom when they all reach Wall Street, where sanity will be forced to prevail. You can see something like that happening with the plodding progress and unenthusiastic anointing of Mitt Romney. It remains to be seen whether the right will be able to get over themselves sufficiently to back Romney or whether Ron Paul will declare as a third candidate just because he can.
I don't despair of DS. He is definitely able to think logically about things and as time goes on and he learns more of life I think he will be able to accommodate more factors into his thought process than he does at the moment. Right now he is in the grips of the late teen early twenties tunnel vision thing that many young men get. It allows them to be very single minded about studying when it is really necessary, pull off great exam results after years of swinging the lead, and single-mindedly pursue careers. That will change, and partly because there is more to Catholicism than a list of Thou Shalt Nots.
His beef with Rick Santorum is that he seems to have an improper understanding of the disestablishment clause (which is not as simple as separation of church and state, which is a colloquial sort of shorthand for it but doesn't really grasp its essence.) I personally think the longer the race goes on the more likelihood there is of Rick Santorum succeeding in making Romney look good.
WRT abortion or one-issue voters, DS thinks (like me) that to vote for someone because you have isolated one issue on which you agree with that candidate is an abuse of your voting privilege. He also believes as I do that abortion will probably never be repealed in the US and that even if it was, abortions would still be performed; like me he believes there is a wider context to abortion that makes this inevitable. Last time we discussed the matter we sort of agreed that opposition through voting to legal abortion alone doesn't fulfill your duty as a practising Catholic and that having a baby and bringing it up is not as easy as it should be in a country where people are not shy of proclaiming themselves pro-life. DS would not vote Republican because most Republicans support the death penalty -- this goes against the tenets of the Catholic church just as much as abortion does. He might find himself without any appealing candidate to vote for for a few years.
As far as voting in accord with his religious beliefs then, I think DS would do this and I think he will eventually be inclined to support a Democratic candidate as his understanding of his religion widens.