One really smart thing that Romney has done is he never got into these silly arguements with Ron Paul like Santorum and in 2008 Guliani did and Perry kind of did it too.
You don't understand. Ron Paul is working to get Romney the nomination. Ron Paul is Romney's attack dog.
Ron Paul attacks any candidate Romney sees as a threat. They can either let Ron Paul's dishonest attacks stand or they can try to respond with the truth. If they try to respond with the truth they end up on the defensive and distracted from the points they want to make.
Ron Paul spent millions of dollars on ads attacking Newt. Ron Paul viciously attacked Michelle Bachmann. Ron Paul never attacks Romney.
Ron Paul spent millions of dollars on ads calling Santorum fake. The moderator and Romney help Ron Paul attack. Santorum was forced into the defensive. This is all part of Romney's strategy.