Its a mistake to try to change people's minds on any issues. Just list off Ron Paul's positive characteristics and tell them how you don't agree with Paul on a number of issues but since he's the most honest person running you have no choice but to vote for him.
"His position on Iran is unpopular, but he's the only veteran in the field and he's gotten more donations from the military than all other candidates combined, so when it comes to the military he's a net positive. Ronald Reagan even commented how he's strong on national defence."
Having a sales job, I can tell you that if someone brings up a negative I'll usually just give it to them if I think I can do that and still get the sale. X is expensive. Yeah, but you get what you pay for. Its cheaper over there. Maybe you should go over there but of course if you do then there is disadvantage X. Or, sure X is expensive, but look at Y.
Sure, the Iran war position may be bad but look at his position on the economy.
Maybe you should go to Cain, but keep in mind the way Cain flip flops on the military issues, he'll probably have Ron Paul's position on Iran two or three times by the end of his term. I'm just so tired of the flip floppers. You?
PS - Its not too late for the sale. Next time you see her tell you can "totally understand her position on Iran" and "sorry I was so hard on you". You can say it isn't really Paul's position on Iran that appeals to you. Rather, the economy is the really important thing and Paul is the only one who predicted the stock market bubble and the housing bubble due to the fact he understands economics but none of the others in the field understand it.
