Americans begin the process of selecting their next president on Jan. 3 in Iowa, where Republicans will gather in small groups to vote for one of seven contenders for their party?s presidential nomination.
Public opinion surveys show former House of Representatives speaker Newt Gingrich surging into the lead over former Massachusetts governor Mitt Romney.
Gingrich leads the latest national polls and has big leads in surveys of two early voting states - Iowa and South Carolina.
?You have a chance, with your friends and neighbors, to make history because virtually every political reporter in America is going to be here,? Gingrich told voters in Iowa.
The former house speaker is the latest Republican to emerge from a large field of contenders trying to position themselves as the conservative alternative to Mitt Romney.
Romney has focused his campaign on winning the New Hampshire primary, to be held one week after the Jan. 3 Iowa caucuses.
For the most part, Romney has focused his rhetoric not on his Republican rivals, but on President Barack Obama and his economic record.
?President Obama is a nice guy," he told New Hampshire voters. "But I don?t think he understands America. I don?t think he understands our economy. I don?t think he understands the power of free people, free to choose their course in life.?
Public opinion surveys suggest the Republican field is narrowing into a two-man race between Romney, the longtime frontrunner, and Gingrich, the latest contender to gain momentum.
But several other Republican contenders have seen their fortunes quickly rise and fall in the polls, including Minnesota congresswoman Michele Bachmann, Texas governor Rick Perry and Georgia businessman Herman Cain.
Cain suspended his campaign after allegations of sexual misconduct and the remaining seven Republican contenders are scrambling to win over his supporters.
?The Republican race has been the most chaotic that I have ever seen, the most unpredictable," says political analyst Stuart Rothenberg. "Anybody who tells you that they expected it to proceed this way, they are fooling with you.?
Romney was considered the 2012 Republican frontrunner after establishing himself as a serious contender when he ran for the nomination four years ago.
But Gingrich's surge in the polls might signal a drawn-out battle for the Republican nomination.
?This is very troubling news to Mitt Romney, who had this air of inevitability," ABC political analyst Matthew Dowd says. "That has now been popped. This poll has shown it is now gone. We could be headed for a very long process in this.?
Romney is having trouble convincing Republicans he is a true conservative, according to analyst Rothenberg.
?The race in one respect is pretty clear. A quarter of the Republican Party wants Mitt Romney and the other three-quarters want to have nothing to do with him.?
For his part, President Obama is trying to rally his fellow Democrats.
?We are not backing down. We are not giving up," he said last week at a rally in New York. "We are going to keep pushing and we continue to fight. And we still hope and are going after the change we believe in.?
Given the state of the U.S. economy and the president?s low public approval ratings, Rothenberg says Obama faces a challenging reelection bid.
?Presidents get the credit when times are good and they get the blame when times are bad, and voters are still in a mood for change, just as they were in 2006, 2008 and 2010. And he represents the establishment.?
U.S. voters will make the final judgment on the 2012 campaign when they go to the polls on Nov. 6.