Public Policy Polling has bad news for Barack Obama: You’re no longer in the lead.  With fifteen months to go and the Republican nominee not yet chosen, Obama has fallen into a tie with Mitt Romney in the Democratic pollster’s latest head-to-head matchup:

For the first time since last July Barack Obama does not lead Mitt Romney in PPP’s monthly national poll on the 2012 Presidential race. Romney has now pulled into a tie with the President at 45%.

Obama’s approval rating this month is 46% with 48% of voters disapproving of him. There are 2 things particularly troubling in his numbers: independents split against him by a 44/49 margin, and 16% of Democrats are unhappy with the job he’s doing while only 10% of Republicans give him good marks. Republicans dislike him at this point to a greater extent than Democrats like him and that will be a problem for him moving forward if it persists.

Romney takes advantage of those 2 points of weakness for Obama. He leads the President by 9 points with independents at 46-37. And he earns more crossover support, getting 13% of the Democratic vote while only 8% of Republicans are behind Obama.

It’s not as if PPP didn’t try to give Obama every advantage in the survey.  Their sample has a D+9 advantage, 42/33/25, which is more than just a little off from 2008’s exit polling, which showed a 39/32/29 split.  The PPP poll has another question which asks respondents to name the candidate for whom they voted in 2008, showing an edge for Obama 47/44 — with 8% unsure.  I’d guess with that sample that the 8% voted for Obama and don’t want to admit it now.

Obama gets a 46/48 approval rating even with the friendly sampling, which PPP calls “poor.”  Among independents, who got undersampled in this survey, it’s 44/49.  They still narrowly favor Obama over Congressional Republicans in the debt-ceiling debate, but only 44/42.  In the head-to-head matchups, Obama only gets over 50% against Sarah Palin (53/37) despite the sample skew, beating Michele Bachmann by only 7 at 484/41, Tim Pawlenty by nine at 48/39, and only getting to 48% against Herman Cain, 48/36.

That’s not a portrait of an incumbent rolling toward victory.  It’s the picture of an electorate looking to make a change.