President Barack Obama moved back to a 5-point lead over Mitt Romney, halting the Republican nominee's post-debate momentum. Obama now leads Romney 50 percent to 45 percent in Gallup's daily tracking poll.

Romney had seen a big three-day post-debate move in the Gallup daily tracking poll, but today's results signal that his debate bump is beginning to level off.

Earlier on Monday, Gallup released results of three days of post-debate, which showed that Romney had tied up the race with Obama in those three days of interviews. It also found that Romney was the biggest winner in the history of the presidential debates.

Obama's approval rating — which has swung wildly in recent weeks — also ticked up to 51 percent, above the "safe" 50-percent threshold for an incumbent's re-election.

Obama also bumped back up in the Rasmussen daily tracking poll. He is now tied with Romney after trailing by 2 points on Sunday.

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