Would President Ronald Reagan be able to run on the GOP ticket if he were alive today?

Yes he would. What happened during his time as president speaks for itself. He took over for one of the worst presidents in history(the current one will rival Caters place) and turned it all around. Within three years the trends and direction of the economy was obvious. He adjusted his policies as the economy got on track. One of the things often forgotten about his term was that he had to rebuild the military. Carter had decimated it and it was one area that truly needed attention and it is also where much of the government spending went. The policies that were put in place were in many areas, directly resulted in the prosperity of the Clinton era.