All other things are never equal.
Reagan was clearly past his prime—and yet he was by far the best choice we had when he was elected.
Bachmann is as conservative or more conservative than any other formal or potential candidate, and she is over 50, a personal preference of mine.
The only question with Bachmann is electability, but she’s not alone there, either.
Reagan was still quite vigorous at 69. His writings between 1976 and 1980 suggest someone who was still quite intellectually dexterous. I have no regrets with his overall presidency and legacy.