From NBC's Domenico Montanaro

Obama leads Clinton 51%-39% nationally, according to a new USA Today/Gallup poll. McCain leads Huckabee 61%-23%.

In the last poll, conducted Feb. 8-10, Obama and Clinton were in a statistical tie with Obama ahead 47%-44%.

The poll was conducted Feb. 21-24 and has a margin of error of +/- 3% for Democrats and +/- 4% on the GOP side.

NOTE: This is the USA Today/Gallup poll, not the Gallup Tracker poll, which shows a slimmer margin.