As IVN’s Kymberly Bays recently reported (http://ivn.us/2012/05/14/gov-romney-worry-less-about-rule-38...), this exact question has already been resolved at the US Supreme Court level: the national party’s rules take precedence over state laws because as a private organization, a political party has the constitutional right as a free association of individuals to set its own rules. State laws interfering with that private process violate a political party’s First Amendment rights.
The Supreme Court case is Democratic Party of United States v. Wisconsin.
Cut from the following article: http://ivn.us/2012/05/16/a-first-ballot-rebellion-in-tampa/
So what are the RNC rules? A 2008 legal representative of the RNC responded to a Mitt Romney supporter's challenge as follows: “The RNC does not recognize a state’s binding of national delegates, but considers each delegate a free agent who can vote for whoever they choose, and the national convention allows delegates to vote for the individual of their choice, regardless of whether the person’s name is officially placed into nomination or not.”
The RNC says delegates are free agents who can vote however they choose - and the Supreme Court has said Party rules take precedence of state law. Thus, state law cannot be enforced against delegates who vote for Ron Paul or any other candidate - state binding notwithstanding.