According to the Associated Press, a record-breaking black turnout surpassed the white turnout in the 2012 presidential election. I surmise the white turnout decreased due to unfavorable views of Mitt Romney (such as his "I don't care about the very poor" and anti-union comments). Many white voters stayed home for the presidential election rather than voting for either candidate. Given a history of voter disenfranchisement, black voters turned out in droves to keep President Barack Obama in the White House.
(AP) — America's blacks voted at a higher rate than other minority
groups in 2012 and by most measures surpassed the white turnout for the
first time, reflecting a deeply polarized presidential election in which
blacks strongly supported Barack Obama while many whites stayed home.
people voted last November at the same rates they did in 2004, when
black turnout was below its current historic levels, Republican Mitt
Romney would have won narrowly, according to an analysis conducted for
The Associated Press.
Census data and exit
polling show that whites and blacks will remain the two largest racial
groups of eligible voters for the next decade. Last year's heavy black
turnout came despite concerns about the effect of new
voter-identification laws on minority voting, outweighed by the desire
to re-elect the first black president.