I hope so. IIRC it was when Romney became the presumptive nominee, rather than the general that Rush started to back him.
That would make sense. I might have been hearing what I wanted to hear but even then, I never sensed that Rush was all that enthusiastic in his support of Romney. I suspect that if Rush were asked who he wanted to be the 2012 Republican nominee, he would have named a hundred people before he would have mentioned Romney.