After long saying he wouldn't run, sources close to New Jersey Gov. Chris Christie say he is reconsidering his decision to stay out of the race for the White House in 2012 and is expected to make a decision soon.

Those close to the first-term governor, who spoke only on condition of anonymity because they were not authorized to speak publicly on the issue, say he is rethinking his hard stance.

A decision will have to come fast as the filing deadlines for primary states are weeks away and Christie would need to put together a campaign team in just a matter of weeks.

Calls have been intensifying from top GOP donors and party elders for Christie to jump into the race. President Barack Obama's weak approval ratings and a Republican field that has been struggling to put forward a clear front-runner are also creating an opening for Christie.

Christie may think twice about moving forward, however. GOP latecomers have jumped in to see a big initial splash, only to tread water.

Michele Bachmann leapfrogged ahead of Mitt Romney only to be pushed back when Texas Gov. Rick Perry joined the field in August after months of insisting he had no interest. But after two shaky performances at debates, Perry now, too, seems vulnerable to getting picked off.