The survey, conducted Dec. 12-16 for The Tribune by Washington, D.C.-based Mason-Dixon Polling & Research, has a margin of error of plus or minus 3.1 percentage points.
"The poll reflects a great deal of uncertainty among voters about their options," says Republican strategist Mark McKinnon, a former top adviser to 2008 GOP nominee John McCain. "The presidential contest is a long way from being settled."
Republicans, just two weeks away from the Iowa caucuses, appear to be more engaged, with only 13 percent undecided. But there's still a wide range of support among the GOP candidates.
Among GOP voters in the survey, Romney and Gingrich are in a statistical tie, 30 percent to 29 percent. A Washington Post-ABC News poll of Republicans, released Tuesday, also showed the two in a dead heat nationally, with each grabbing 30 percent.
Romney is the only Republican who fares well in a head-to-head showdown against Obama, with each garnering 47 percent of registered voters, according to a similar Post-ABC News poll. Obama has more than a 10-percentage point lead against Gingrich in a separate hypothetical matchup as polled by Rasmussen Reports this month.
In the Tribune poll, Texas Gov. Rick Perry takes 10 percent of the Republican vote followed by Rep. Michele Bachmann, R-Minn., at 7 percent and Rep. Ron Paul, R-Texas at 6 percent.
Former Utah Gov. Jon Huntsman trails at 1 percent among all U.S. voters and 1 percent among fellow Republicans.
Obama snags 33 percent of the nationwide independent vote, followed by 17 percent for Romney and 12 percent for Gingrich. Nearly a quarter of independents remain undecided.
Brad Coker, managing director of Mason-Dixon Polling & Research, notes that the combined Republican support far outweighs those who say they want to re-elect Obama, 45 percent to 37 percent. But 18 percent of all likely voters are unsure who they back, Coker says, showing that "a lot of people are not really thinking about this."
The Tribune poll mirrors other national surveys, even though the question did not identify the possible candidates; voters were simply asked to name their pick.
Coker also points to the 13 percent of undecided GOP voters as evidence that "Republicans are tuned in. They are starting to take sides, and they know about the candidates."
Obama garners 2 percent of the Republican vote, according to the poll, while Romney gains 5 percent and Gingrich 2 percent from Democrats.
The margins of error in the party results range from 5.2 percentage points to nearly 6 percentage points.
Poll respondent Elsie Robinson, a nurse from Milwaukee, says she voted for Obama in 2008 and plans to do so again in 2012. Her decision comes down to more of what she fears from the other side than what Obama could accomplish.
"He would fight to keep Social Security and certain things that the tea party doesn't want," she says of the hard-line GOP faction. "That's what I'm voting against the tea party."
Julian Zelizer, a professor of history and public affairs at Princeton University in New Jersey, says the poll shows some distance Obama will have to cover with Democrats and independents, but adds that it's not a bad spot at which to start the election year.
"He's still in a stronger position than the Republicans," Zelizer says, "and that comes with incumbency and comes with the disarray of the Republican Party."
Romney can find good news in the poll, too. First, he comes the closest again to Obama's numbers and, second, he stands to pick up voters now backing other GOP contenders as the field winnows.
"That support is divided among many people now, but that support will go his way," Zelizer says. "Some undecided [voters] could go to Romney; they won't necessarily go toward Gingrich."
More poll results coming Thursday
P Should a candidate's faith play a role in presidential politics?