Another poll finds President Obama in a better position after last week's Democratic convention.

Fox News has Obama leading Mitt Romney 48 to 43 percent among likely voters, a four-point shift from before the convention (but within the poll's margin of error.)

Like other pollsters, Fox found that Obama had caught up with Romney in enthusiasm, with supporters of both candidates now equally likely to say that victory is "extremely important." 

CNN also gave Obama a convention bounce with likely voters; a Washington Post-ABC News poll found a bounce with registered but not likely voters. 

The Fox News poll gave Obama a five-point bounce with women and a 12-point bounce with independents. But Post-ABC News polling actually showed the opposite swing -- Romney now has a 54 to 43 percent edge among independent likely voters, compared with 49 to 44 just before the conventions. CNN also showed Romney increasing his support among independent voters.

The size of independents varies from poll to poll, along with their party lean, and likely voters are defined differently by different pollsters, so its not surprising to see variance. Fox News doesn't explicitly offer respondents "independent" as an option, resulting in a smaller pool of independent voters (19 percent) than our most recent poll (36 percent).
Romney needs to outperform Obama with independents to win, because more people identify as Democrats than as Republicans.