For the second time in a week, Mitt Romney is in New Hampshire.

Mitt Romney is cheered on by supporters and Sen. Kelly Ayotte ( R-N.H.), left, outside City Hall in Nashua, N.H., last year. (Photo/Winslow Townson)

Romney hits the trail Monday morning with Sen. Kelly Ayotte, the New Hampshire Republican who is one of Romney’s top backers in the Granite State. The two will appear at a campaign rally in Portsmouth at 11 a.m.

Who is Kelly Ayotte?

The GOP freshman and former state attorney general won election to the Senate in the 2010 tea party sweep.

She’s frequently floated as a potential contender for the vice presidential slot, along with Sen. Marco Rubio (Fla.), with whom Romney campaigned outside Philadelphia last Monday, and others including House Budget Committee Chairman Paul Ryan (Wis.), Virginia Gov. Bob McDonnell and Ayotte’s fellow Senate freshman, Rob Portman of Ohio.

While Ayotte may lack the national name recognition of some other top GOP figures, she could give Romney a lift by bringing gender diversity to the presidential ticket. The fact that Ayotte also hails from New Hampshire – a swing state that Romney hopes to turn red this November – could also be a boon for her vice presidential chances.

Today won’t mark the first time Ayotte has campaigned with Romney; the two stumped together ahead of January’s New Hampshire primary.