Yesterday, Drudge blared the news that Obama was leading McCain by 9 points in Gallup's daily tracking poll, but the latest Gallup/USA Today poll shows Obama trailing McCain by 4 points:

The Friday-Sunday poll, mostly conducted as Obama was returning from his much-publicized overseas trip and released just this hour, shows McCain now ahead 49%-45% among voters that Gallup believes are most likely to go to the polls in November. In late June, he was behind among likely voters, 50%-44%.

Jim Geraghty is skeptical about Gallup's apparently contradictory polls. But one explanation for the conflicting results is that the daily tracking poll--which shows Obama up by 8 points today--is a survey of registered voters, while the poll showing McCain up by 4 points only included "likely voters".

That would indicate that Obama is the one suffering from a huge enthusiasm gap.

Of course, Gallup might be off. Rasmussen's daily tracking poll of "likely voters" shows McCain down by 3 points.

What's clear is that the race is close. An average of polls compiled by Pollster.com shows Obama up by 4 points, and the Real Clear Politics average shows Obama up by 3.