Today’s Gallup seven-day tracking poll shows Mitt Romney with a solid lead against President Obama among likely voters. At NRO, Charles C.W. Cooke reports on why this poll is historically meaningful:

Mitt Romney is up six points on Gallup’s seven-day likely-voter tracker, 51–45. Romney is also winning the seven-day registered-voters poll, 48–46.  These statistics are there to be broken, but it is worth pointing out for the record that, in the history of Gallup, no presidential candidate has ever been over 50 percent in mid-October and gone on to lose.

Going into the 2008 election, Obama had a 7-point lead on Sen. McCain, 53.5 percent to 46.5 percent in the same Gallup tracking poll. This is almost a complete inversion of that. We’re less than three weeks away from the election, but there’s still time for Obama to halt Romney’s momentum. The president scored a narrow victory in last night’s debate, but it’s not clear whether it was enough to make a difference in the race. The CNN snap poll found most debate-watchers said it didn’t influence their vote, and the ones who said it did were split evenly between the two camps:

The president’s edge on the question of who won the debate appears to be the result of his much better than expected performance and his advantage on likeability. But the poll also indicates that debate watchers said Romney would do a better job on economic issues. And the two candidates were tied on an important measure – whether the showdown would affect how the debate watchers will vote. Nearly half said the debate did not make them more likely to vote for either candidate, with the other half evenly divided between both men.

That doesn’t mean Obama won’t get any boost from last night, but the benefit for Romney was apparent almost immediately after the first debate.