Donald Trump just lost his lead in the only major national poll left to show him ahead

The only major national poll that consistently showed Donald Trump ahead of Hillary Clinton has, with the wave of polls swinging dramatically in favor of the Democratic nominee, also has shifted in her favor.

On Wednesday, Trump trailed Clinton in the Los Angeles Times/University of Southern California by 0.4 points. It was the first time he was behind in the poll since September 11 - ending a monthlong stretch in front in the head-to-head matchup.

The poll skews more favorably for Trump because it relies on past voting preferences, which experts say is a potentially perilous method of sampling because of voters' tendency to misreport whom they've voted for in the past.

Trump's support has collapsed in the days that followed Friday's shocking revelations from a leaked tape, in which he boasted he could "grab" women "by the p---y" because "when you're a star they let you do it."

Clinton has gained nearly 2 points on Trump in the RealClearPolitics average of several polls in the days since the 2005 tape leaked. She leads by an average of 6.2 points in the head-to-head battle.

Other polls released Wednesday found Trump well behind Clinton in the key swing state of Ohio and tied in Utah, a state that has traditionally voted for Republican presidential candidates.