I think they are likely both very smart men.
The best way to guess is to compare academic achievements...
Cheney- dropped out of Yale due to bad grades, eventually got a BA and MA at University of Wyoming. Bailed on a PhD dissertation at University of Wisconsin.
Obama- well, maybe we don't need to go further.
He who knows the least obeys the best.
Gore dropped out of divinity studies and law school at Vanderbilt
Kerry went to the fourth best law school in Boston while Bush went to the best Business School in the USA.
that's a stupid measure of intelligence. Obama never would have been accepted into Columbia or Harvard if he had been the same color as Cheney