McCain's victory casts the Jan. 15 Michigan primary in a new light. Romney is a Michigan native whose father was a revered governor there while Huckabee hoped to gain momentum from the state's evangelical base, The New York Times said Wednesday.
Former New York Mayor Rudy Giuliani, meanwhile, is hoping to launch his campaign by winning Florida's primary Jan. 29, ahead of "tsunami Tuesday" Feb. 5, when more than 20 states have primaries elections.
Former U.S. Sen. Rick Santorum, R-Pa., told the Times the battle for the GOP presidential nomination indicates a lackluster field of candidates.
"It comes back to, OK, Romney can't win, Huckabee can't win, McCain can't win, Giuliani can't win -- the dynamic is you have a bunch of candidates who can't win," Santorum said.
The Republican candidates meet Thursday in South Carolina for a debate.