John McCain won the New Hampshire Republican primary Tuesday night, completing a remarkable comeback and climbing back into contention for the US presidential nomination. Barack Obama dueled with Hillary Clinton in an unexpectedly tight Democratic contest. McCain, a US senator, rode a wave of support from independent voters to defeat former Gov. Mitt Romney of the neighboring state of Massachusetts. The showing reprised his victory in the traditional first-in-the-nation primary in 2000, when he defeated George W. Bush. The early front-runner in the Republican race, McCain's candidacy fell apart last year. "We showed the people of this country what a real comeback looks like," McCain told The Associated Press in an interview as he savored his triumph. "We're going to move on to Michigan and South Carolina and win the nomination."