"As any good executive would, let's look at the numbers.
"The only president since Hoover with business experience under whom the economy did well was the one who was unsuccessful in business: Harry Truman, whose haberdashery shop went bankrupt after two years.
"The startling bottom line is that the nation's GDP has grown more than 45 times faster under presidents with little or no business experience than it has under presidents with successful business careers. And on average, when there has been a successful businessman in the Oval Office (so, Truman is excluded), GDP growth has been negligible.
"There is a saying: 'If you want to live like a Republican, vote Democratic.' Perhaps it should be amended to: 'If you want to live like a successful Republican businessperson, vote for a Democrat without business experience.'"
-- Robert S. McElvaine, [web version not dated but URL suggests 2012-10-19] in The Washington Post.
[Note that other, older analysis has shown that even just looking at personal wealth levels and ignoring other business metrics, the rich get richer faster under Democratic administrations than under Republican ones, so you'd think the fat cats would support Democrats. The other difference is that under Democratic presidents the middle class gets richer as well and the poor aren't let behind quite as badly, while under Republicans the rich are a little less well off and everybody else is much less well off than under Democrats. Apparently these 'captains of industry', 'job creators', and 'people who are really smart about money' really suck at voting for their actual best interests.]