Doubt it. Romney is a stronger candidate than McCain, he would not have picked Palin as his running mate
When will this myth die? Have you not learned anything from 2016? The Palin pick was great from McCain, it gave his struggling campaign a huge boost out of the convention and he was leading Obama in the polls until Lehman Brothers happened.
Palin was a 100x smarter pick than the Romney pick of Ryan in 2012, which got the GOP ticket eviscerated by being tied to the Ryan's Medicare vouchers for seniors plan.