Consider: Barack Obama has 250,000 donors, a small minority of whom have contributed the maximum $2300 for the primaries. A comparatively higher percentage of Hillary Clinton's donors have maxed out. Obama has many more potential wells to tap. So sheer interia is one reason he may outraise Clinton again.

As the end of the quarter approaches, the campaign is pairing up small donors and asking each of them to match the other's contribution.

Campaign manager David Plouffe sent an e-mail yesterday to the campaign's 250,000 donors. One of those donors forwarded the e-mail along.

"I know this is not a novel approach, but I love this idea," the donor writes. "I originally gave $50 back in [redacted] and have been trying to figure out a way to get the most ‘bang for my buck’ on another $50 contribution. This works perfectly."

In the e-mail, Plouffe describes the process:

You choose the amount you're willing to match.

If you want, you can write a message to a potential donor about why they should own a piece of this campaign.

Then you wait. Soon you'll be matched with a fellow Obama supporter who's making their first donation because of your promise to match their gift.

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