News analysis: Measuring the Pres. Obama post-convention bounce

President Barack Obama's bounce coming out of last week's Democratic National Convention has him clearly ahead beyond the margin of error in two key polls early this week. Both the Rasmussen and Gallup tracking polls show Obama leading 50-45.

Some Republicans are fearful, while others urge skepticism and historical perspective.

Democrats, meanwhile, are gleeful, and some see the shift from last week's dead heat as vindication.

"The movement in Obama’s direction reinforces a point that many neutral campaign observers have been reluctant to make for months now," wrote Steve Kornacki at Salon. "The presidential race is not, and has not been, a virtual tie — Obama is, and has been, winning."

Rich Lowry at National Review spoke with a Romney adviser, who strongly resisted the notion that this week's numbers are the new status quo.

"Nobody in Boston thinks we’re going to lose," Lowry's source said. "We’re in a tight race. We had a 4-5 point bounce after our convention and it evaporated when they had theirs. Now they have a 4-5 bounce. It’s going to evaporate in September. We feel good about the map. We’re up with advertising in Wisconsin, and I think North Carolina is going to come off the board. On Ohio, they’ve been spinning for months now that it’s out of reach."

Romney's operatives have a natural incentive to spin. To a lesser degree, this is true of partisan analysts, like Jay Cost at the Weekly Standard.

Cost says that historically the Gallup polls at this point have been a weak predictor of final outcomes. "The only challenger who successfully defeated an incumbent and had a comfortable lead all through the pre-convention summer period was Jimmy Carter in 1976," Cost wrote. "Both Ronald Reagan in 1980 and Bill Clinton in 1992 were stuck in basically the same position as Romney was prior to the conventions."

"Obviously, all of this could change. Historically speaking, convention bounces tend to be exactly that — bounces that fade over time. Romney enjoyed a modest bounce, and so far it looks like Obama is enjoying a 4-point bounce or so. My instincts tell me that by the time of the debates, we will be back to precisely where we were in August — both candidates essentially tied and stuck 3-5 points below 50 percent," Cost concluded.

Nate Silver at the New York Times is Cost's opposite number: a partisan analyst who wants to be right as well as see his side win. Noting the shift toward Obama, Silver expresses measured optimism about how well the shift will hold up.

"How far will Mr. Obama’s numbers rise, and how long will his bounce last? We don’t know that, of course. But the range of possible outcomes reads pretty favorably for him," Silver wrote.

"As I wrote on Saturday night, Mr. Obama’s polls could easily cool off quickly," Silver concluded. "If we return to the equilibrium where Mr. Obama is about two points ahead in the polls — about where they were for months on end heading into the conventions — then Mitt Romney’s position won’t be too badly damaged. Still, Mr. Romney will be the underdog, and he’ll have had two or three weeks of time run off the clock."

Eric Schulzke writes on national politics for the Deseret News. He can be contacted at eschulzke@desnews.com.