This is the first CBS News poll to include the vice presidential candidates in the horserace question.
The eight-point lead for the Democratic ticket is up from Obama's three-point lead before the convention. But there are still a significant number of voters who have yet to firmly make up their minds.
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Post-Democratic Convention Poll
Before the Democratic convention, McCain enjoyed a 12-point advantage with independent voters, but now Obama leads among this group 43 percent to 37 percent. Obama's lead among women has also grown to 14 points (50 percent to 36 percent), and the Democrat maintained the lead he had before the convention among voters who supported Senator Hillary Clinton in the Democratic primaries.
The poll shows an increase in the number of Obama voters who are enthusiastic about him. Sixty-seven percent of Obama voters say they enthusiastically support him, which is up from 48 percent who said so before the convention. About a quarter of McCain's backers are enthusiastic about him--unchanged from before the Democratic convention.
Sixty-three percent of registered voters say Obama understands their needs and problems, while just 41 percent say that about McCain. And after the Democratic convention, 58 percent of voters say Obama is "tough enough," which is up from 48 percent in early August.
Though Obama has seen his lead grow, there are still areas where he has room to improve. The latest CBS News poll shows no change in the percentage of registered voters who say Obama has prepared himself well enough for the job-- a sentiment in which McCain has held a large advantage. But fewer voters now say Obama is not prepared for the job of President than before the convention.
Although 50 percent of voters now say that Obama has made it clear what he would do as president (up from 41 percent), 44 percent still say the Democratic nominee has not made it clear.