New Jersey Gov. Chris Christie says it'll be tough for the Republican nominee to unseat President Obama in 2012.

The Republican says it's possible for his party to take the White House next year -- especially if unemployment remains high. But he cautioned against underestimating the incumbent president's political savvy.

Christie was asked to handicap the contest during a live interview on Facebook.

Monday's 45-minute interview was streamed live from the social networking site's Palo Alto, Calif. headquarters.

Christie has endorsed former Massachusetts Gov. Mitt Romney.

Christie decided not to seek the nomination himself despite urgings from wealthy GOP donors.

The governor says he'll campaign for Romney, but he expects Obama to be a formidable and well-financed opponent.

Christie's own possible White House bid will wait at least till 2016.