Why did 9% of those who approved of Obama vote for Romney?

[IceSpear]

According to the exit poll, Obama's approval was 54-45 among election day voters.

Among those who disapproved, Romney won 94-3. Among those who approved, Obama won 89-9. Does this make no sense to anybody else? You'd think if anything a president would outperform their approval numbers, due to a small "I disapprove of them, but they're still the lesser of two evils"/devil you know rather than the devil you don't factor. Was this just an exit poll error?

[Pragmatic Conservative]

Some could have approved of Obama, but just preferred  Romney. Their are lots of examples of people getting less support then their approval rating.

[Sumner 1868]

Mormon Democrats.

[Fmr President & Senator Polnut]

Some could have approved of Obama, but just preferred  Romney. Their are lots of examples of people getting less support then their approval rating.

Yeah, it's not that discombobulating. You have dyed in the wool types who would vote Dem of GOP regardless of what you think of the incumbent.

[TJ in Oregon]

There is probably some segment of the population who simply approves of everyone.

[Smash255]

Some of it might be moderate middle class suburbanites, but its certainly not that unheard of.  When Chaffee lost his re-election bid to the Senate his approval was 63% according to the exit poll.   Granted, that was a bit more of an extreme example with him being a Republican, in a brutal Republican year, in a state with ten Republicans.

[SingingAnalyst]

Sampling error, response bias (order of questions, nature of interviewer, etc.)

[SingingAnalyst]

The thing I recall is in 2010 when something like 23% of those who disapprove of the GOP voted Republican for Congress; perhaps this was a lesser of two evils thing.