On the same day that $100 million-plus heiress/candidate spouse Cindy McCain says, "How about never? Is never a good time for you?" with regard to when she’ll release her tax returns, the Associated Press profiles the most fearsome financial powerhouse of the 2008 election:

Kriss Riggs isn’t one to spend her money on politicians.

"Even the place you can donate a dollar on your taxes, I refuse to do it," says the 60-year-old photographer from Blue River, Ore.

Likewise for Kate Schwartz, a 24-year-old marketing expert from Chicago. Past elections, she says, always seemed far removed from young people.

"A lot of people felt like it wasn’t happening in my demographic," Schwartz said.

Not this time.

Riggs and Schwartz are foot soldiers in Barack Obama’s 1.5-million-strong army of campaign contributors. Dozens of Associated Press interviews with donors, and an AP financial analysis show how contributions that make only a soft ca-ching by themselves, arriving in increments of $10, $15 and $50, have collectively swelled into a financial roar that has helped propel Obama toward the Democratic president nomination.

Altogether, Obama’s campaign has taken in an unprecedented $226 million, most of it contributed online. His donor base is larger than the one the Democratic National Committee had for the 2000 election.

These are hardly political fat cats. Ninety percent of his donors give $100 or less, and 41 percent have given $25 or less, according to the Obama campaign.

I think I like this contrast on the subject of public accountability — or, to put it in less jargonesque language, knowing who you work for — going into the fall campaign. Barack is likely to be the target of whining from the Double-Talk Express if he chooses to opt out of the general-election public financing restrictions, but all he has to do is point out that the purpose of that funding approach was to keep candidates from being compromised by their reliance on who’s giving them money.

Then he can add, "If John McCain wants to accuse me of being beholden to the nearly 2 million Americans of all backgrounds who have donated money to my campaign, mostly in amounts ranging from 10 to 100 dollars, my answer is… yes! I’m indebted to them, and those are the people whose interests I’ll serve as President."

Go for it, John… I dare you.