Christine O'Donnell may think a lawn gnome can beat Barack Obama next year, but a new Reuters poll says otherwise.

According to the Reuters/Ipsos poll, if the general election were held today, Obama would beat current GOP front-runner Newt Gingrich by a 13-point margin, 51 percent to 38 percent. He would also beat Mitt Romney by an 8-point margin, 48 percent to 40 percent.

Both results are well outside the poll's margin of error of plus or minus 3 percentage points, and they mark a dramatic turnaround from the last Reuters/Ipsos poll, which was conducted from Oct. 31 to Nov. 3 and found Romney leading Obama by 1 point. That poll did not include a matchup between Obama and Gingrich, because Gingrich was at the bottom of the Republican pack at the time.

The results challenge the overconfident assertion made by some Republicans that electability shouldn't be a major factor in the primaries because anyone can beat Obama.

President Obama is wildly unpopular across the United States, Michele Bachmann told Fox News on Dec. 1. That's why the key message is, we don't have to settle. We can have it all in a candidate and we need to have it all in a candidate, because this is a highly unusual election.

Christine O'Donnell, the Tea Party darling who ran unsuccessfully for a U.S. Senate seat in Delaware last year, put it more colorfully: Right now a lawn gnome could beat Obama in 2012, so yes, we can be picky, she told ABC News on Tuesday.  

Not so much.

It is true that Obama's approval rating is 47 percent, but anyone who follows politics should know that a low approval rating does not mean an incumbent can't win. This sort of Republican arrogance would be more justified if Obama's numbers were catastrophically low -- but 47 percent, while far from ideal, is not catastrophic.

If I recall correctly, it was this very arrogance that cost the Democrats the 2004 election. President George W. Bush was very unpopular at the time, but he was still re-elected, in no small part because the Democratic nominee, John Kerry, was decidedly uninspiring. He gave voters a slew of reasons why they shouldn't vote for Bush, but he never convinced voters that they should vote for him.

None of this is to say that Obama will win re-election. He may or he may not: he is doing well in hypothetical matchups at the moment, as evidenced by the Reuters/Ipsos poll, but his low approval rating and the high unemployment rate make him vulnerable -- and besides, a lot can change in 11 months.

But anyone who says he definitely won't win re-election, no matter who his Republican opponent is, is incredibly naïve.