WASHINGTON - Nearly half of Americans are dissatisfied with their choice for the next president, saying they don't think any of the candidates would make a good president, according to a new Gallup poll released Wednesday.

When asked if there is any candidate running who they think would make a good president, 48 percent of those surveyed said yes and 46 percent said no, the poll showed.

Americans' dissatisfaction with the current presidential field is much higher than in 2008 when only 11 percent said none of the candidates would be a good president.

The results might, to some extent, explain the volatility of the Republican nomination race, with no strong and sustainable front-runner having ever emerged so far in this campaign.

A number of Republican candidates -- including former Massachusetts Governor Mitt Romney, Texas Governor Rick Perry, businessman Herman Cain who dropped out early December -- had surged to the top of the field but only to drop even more rapidly. Former House speaker Newt Gingrich, the current front-runner, has recently shown signs of losing momentum, too.

With less than two weeks until Iowa kicks off the nation's first caucuses on Jan 3, many Republican primary voters are still undecided about whom they will finally vote for, according to recent polls.

The weakness of the Republican field is surely a good news for President Barack Obama who is seeking a second term. The White House incumbent had admitted in some interviews that he was an " underdog" in this contest primarily due to the nation's economic woes.

However, there have been positive signs for the president's reelection campaign. According to a CNN survey released Tuesday, 49 percent of Americans approve of the job Obama is doing as president, up five points from last month, with 48 percent saying they disapprove, down six points from mid-November.