A solid majority (56%) give the Obama campaign letter grades of A or B for the job he is doing to convince the American public to vote for him, while only 32% say the same of the McCain campaign. More than a third (35%) offer a grade of C to McCain's campaign so far, and nearly as many (30%) say the campaign has earned a D or F.

The grades voters give to the Obama campaign for the job it is doing convincing them to vote for him are the highest measured for any candidate over the past four election cycles. In June 2004, for example, just 39% gave Bush's efforts an A or B; even fewer gave high grades to Kerry's campaign (31%). In contrast, McCain's middling grades are slightly lower than those awarded to Bush in both 2000 and 2004. McCain's campaign does garner higher grades than the 1996 Dole campaign, which only 22% graded highly.

In this regard, the 2008 campaign has the largest disparity in high grades for the Democratic and Republican candidates over the past four election cycles (24 points). The gap between the grades for Obama and McCain is even larger than for Bill Clinton and Bob Dole in July 1996; at that time, 37% gave Clinton an A or B, while just 22% gave top grades to Dole.

(LA Times)