The other states are called toss-up states or swing states because the polls show it will be a close race. Two important states used to be toss-up states but now those states (Wisconsin and Ohio) belong to President Obama. He can't possibly lose in those states. There are 7 swing states left.
But what if Obama wins New Hampshire, and Romney, despite the impossible odds, wins the other six swing states. Then each candidate would win exactly 269 electoral votes, so both Obama and Romney would not have the required 270 votes to win the election. Then the United States House of Representatives would vote for our next president and their decision would be final. Since Republicans are the majority in the House (the Democrats are the majority Party in the Senate but the Senate can't make this decision according to our constitution), it's fair to say Romney would win. So all Romney has to do is win six swing states even though the polls show Obama will win all seven swing states. It can't be done. It's impossible. I have a better chance of winning the lottery and I never buy lottery tickets.