Chart above, and story, via Huffington Post:
Small-donor contributions make up nearly all of the Obama campaign’s fundraising lead over the Romney campaign. Obama for America, the official campaign committee, has raised $157 million more than Romney for President through the end of August. Remove the small donors, and that lead shrinks to only $14.7 million.
Romney’s campaign has been unable, either because of the candidate’s lack of a strong connection to his party’s base or because of the inadequacies of its online and direct mail efforts, to raise these small contributions in anything close to the same numbers. Obama has pulled in $189 million from small donors, while Romney has received a comparatively tiny $46.7 million.