Rieckhoff said there's a group of donors dedicated to veteran issues, but few who give six- and seven-figure sums. The new fundraising aims not only to attract large donations, but recast the giving as a moral obligation rather than an option.

"It's not a question of, Is there money out there'," Green said. "And it's not a question of whether people should give the money. It's only a question of finding them and convincing them to give it."