First off, in the beginning, don't mention Paul's name, or your stance on any of the issues. Ask them questions.
Ask them if they are enjoying paying all of the taxes they are paying now. Then ask them if they want to pay even more since the plans she wants to institue will cost the american people an ADDITIONAL 600-900 billion US dollars.
Proceed to ask Hillary supporters if they think we should be policing the world and getting involved with every country's business. If they say no, tell them it costs about a trillion US dollars a year to continue policing the world as well as maintain MILITARY bases in countries like Germany, Japan, South Korea and many others... then you can kill two birds with one stone by saying, "just so they know" - the Federal Income tax brought in about 1-1.2 trillion US dollars in the fiscal year of 2006 - almost the SAME amount of money. Hillary Clinton will not change either of these policies that Bush among others have maintained. Yes, she may withdraw CURRENT troops in Iraq, but just to start Redeployment. She has stated this.
Ask them if they believe in a free market. Give them the example of technology. One of the last free markets. Technology improves very quickly - so much so its hard to keep up (ask them if they agree, the mroe you get ppl to agree with you ont he smaller issues, the mroe their mind feels obligated to agree with you on a whole - I'm a sales supervisor, and train people how to sell, I know these things). Meanwhile prices decline while the technology itself increases at a significant rate - due to competitive practices. Now mention the heavily regulated markets of health and education (dept of health and dept of education are govt entities designed to heavily regulate these markets), prices are EXTRAORDINARILY high for good education, yet still our scores on tests are declined in the world ranks. As for health... haha... same thing... prices keep rising and the health market has created some very unethical practices. Hillary Clinton supports heavy market regulation.
Say how she has relatively no knowledge in economics and has NO PLAN to get us out of the serious economic crisis we are in and falling into, besides letting the federal reserve continue to do what it's been doing - which has contributed to bringing us to where we are today in the economy (low value dollar, housing market, etc). Ask if they agree.
Ask them if they've heard of "The Patriot Act". Most will say yes. Ask them afterwards "Do you know what it means"? most will say no. Inform them that this act (which was voted for by Hillary AND Obama), allows the government to, if they wanted to - freeze all of your assets, break into your home without a warrant, take you away and torture you - under a mere SUSPICION. No need for any proof whatsoever. Ask them if they think that sounds like a good idea. Most will say no.
There's a solid 6 reasons right there. There may be a couple more. Once they do agree(and most people will, those who dont - dont waste any more time with them and move on), say to them... "So... then why are you voting for Hillary Clinton? She supports all these things which are all detrimental to the american people, the economy and the opinion os the US from the world. Based on your views, you should be voting for Ron Paul."
I have converted about 25-30 people I know to Ron Paul by doing stuff like this. Ask THEIR opinions about stuff the general population hates, and associate "their candidate" with those things (if they do indeed support them, in which case they all do (McCain, Obama, Hillary)). Don't mention Ron Paul until the end, in which you ahve them shocked and appalled at their own candidate - then bust out the Ron Paul hotness.
Virtually ALL of the candidates that have stepped up for candidacy this election have no REAL case for change. EXPOSE it by attaching common miserable practice of the government with "their" canidate, and sell em on Ron Paul AFTER. Don't expose your agenda in the beginning of being a Ron Paul supporter - because that will get them to shut you off in their head right off the bat, because of how the media (and friends) tries to guide everyone's perceptions of him. You need to sneak it up on them.
PS - Barack has stated he WILL get out of Iraq immediately, or so he says, but soon afterward you will see him invading Iran and Syria.