By Gram Slattery (Reuters) -Contenders for the Republican presidential nomination will face off in the second contest of their nominating process on Tuesday in New Hampshire, while Democrats compete there on the same day in a battle expected to be significantly less competitive. The Republican battle is down to two candidates – former President Donald Trump and former U.N. Ambassador Nikki Haley – after Florida Governor Ron DeSantis dropped out of the race on Sunday. The New Hampshire primary comes eight days after Iowa’s Republican caucuses, which former President Donald Trump dominated. Hale…