In 2008, a large turnout among black and Latino voters put President Barack Obama on top in swing states like Virginia and New Mexico. In the run-up to 2012, however, the number of this key electorate registering to vote has fallen, challenging the Obama campaign at its very foundation, according to a report by The Washington Post.

The number of registered Hispanics has dropped significantly — 5 percent across the country, to about 11 million, according to the Census Bureau. But it’s the narrower picture that is more worrisome. The decline among Hispanics is just over 28 percent in New Mexico, for example, and about 10 percent in Florida.

Meanwhile, the registration numbers for blacks are down 7 percent nationwide.