Reagan was popular for two primary reasons: communication ability, and his generally consistent application of a conservative philosophy and theme to every issue. The latter being a sign of higher level intelligence. In contrast, GB was all over the map with no guiding philosophy. Obama stays fairly consistent with a 1960s polemic anti-establishment paradigm that is stuffing delusional helpings of salt into an economic wound that is already too deep and wide to heal.
I think to the average voter, personality and communication style is 80% of why they vote for a candidate, and issues are 20%. The two major parties in the US are more similar than they are different, despite people wasting precious seconds of their lives arguing on the internet about why the other side is evil incarnate.
The Congress, courts, and corporate donors hold sway over many of the important issues, and for the rare times that it does come down to a gut call in a crisis made by the person sitting in the big chair, there's something to be said for having someone thoughtful and unemotional, regardless of their party. My top two choices? Bill Clinton and Dick Cheney. Polarizing figures that probably just caused all of Coastgab to hate me

, but also easily the most savvy and knowledgeable politicians in their respective camps.
Regardless of their politics, I'd want both of them on my side when the shit hit the fan.