Chris Christie's White House ambitions come into play in pig proposal in New Jersey

There are not that many pigs in his home state. But there are millions in the early presidential voting state of Iowa. And that's making for a tough decision for Chris Christie, both New Jersey's governor and a potential presidential candidate.

Christie has until early December to decide whether to sign a bill that would ban pig farmers in the state from using devices called gestation crates. The metal cages are so small that pregnant pigs can't turn around.

The bill has the support of Republican and Democratic state lawmakers in New Jersey. But it is opposed by the pork lobby, which is based in Iowa, a state that's home to millions of pigs. And that could cause problems for Christie if he decides to run for president in 2016.