President Obama may not be enjoying the post-convention bounce many polls indicate.

Many of those surveys were taken among registered voters, some of whom are unlikely to head to the polls in November.

An ABC News-Washington Post poll of likely voters showed the president had a 49-48 lead over Romney. That's basically unchanged from before the Democratic convention.

"Don't get too worked up about the latest polling," Neil Newhouse, Romney's pollster and senior strategist, wrote in a memo. "While some voters will feel a bit of a sugar-high from the conventions, the basic structure of the race has not changed significantly."