Obama Money Machine: How His Presidential Campaign is Doing in Comparison

Obama has established joint fundraising agreements with the Democratic National Committee and two other party committees. Those entities can raise larger sums and spend unlimited amounts on behalf of individual candidates.

Of the $20.3 million Obama's joint fundraising committees amassed in June, 86%, or $17.6 million, came in chunks of $5,000 or more; 64% came in increments of $28,500 or more, campaign finance reports filed over the weekend show.

Even as he touts his base of small donors, Barack Obama is relying heavily on well-heeled contributors who have given $28,500 or more each to Democratic Party committees that will campaign on his behalf.

Obama aides emphasized that the average donation to his campaign in June -- during which he brought in $52 million -- was $68. Over the course of his campaign, the presumed Democratic presidential nominee has raised $340 million. By law, an individual can give no more than $2,300 to a candidate for the primary and $2,300 for the general election.