Following the Iowa caucuses, the focus of the U.S. presidential campaign will shift to the next state to hold its nominating contest, the northeastern state of New Hampshire.

Polls show that former Massachusetts governor Mitt Romney holds a commanding lead among Republicans in the January 10 contest, with more than 40 percent support, averaging 22 points ahead of his closest challenger, U.S. Representative Ron Paul of Texas.

Former House speaker Newt Gingrich places third.

Former Utah governor Jon Huntsman, who was President Barack Obama's ambassador to China, campaigned in New Hampshire instead of Iowa. He places fourth in polls.

Texas Governor Rick Perry and U.S. Representative Michele Bachmann plan to bypass New Hampshire and instead focus on South Carolina, a southern state that holds its primary on January 21. Polls show their support in New Hampshire in the low single digits.

After New Hampshire and South Carolina, the next states to hold contests will be Florida on January 31 and Nevada on February 4.

And in early March, if a clear leader has not emerged, a number of states hold contests on what's called “Super Tuesday”.