"The money in politics is corrupting. It controls everything," Gillibrand told a gathering in Des Moines, Iowa, last month. "You've got to take on the whole system, and you have to get money out of politics. And that's why, as a very small first step, I'm not taking corporate PAC money."
Small as it is, this pledge to reject corporate PAC money has become a cornerstone of the Democrats' primary contest. It helped Harris to raise $1.5 million online from small donors in the 24 hours after she announced. Warren's campaign didn't release a total for the post-announcement surge, but she said she got contributions from all 50 states, the District of Columbia and Puerto Rico.
"Every [Democratic] candidate who has announced that they are running for president has said that they will not take any corporate PAC money," said Tiffany Muller, president of End Citizens United, a political action committee that's been leading the charge against corporate PACs. The group's name refers to the 2010 Supreme Court decision that opened the door to unlimited political spending by independent groups.
Besides Gillibrand, Harris and Warren, those candidates include Sen. Cory Booker of New Jersey, former Housing and Urban Development Secretary Julian Castro; South Bend, Ind., Mayor Pete Buttigieg; Rep. Tulsi Gabbard of Hawaii; and former Maryland Rep. John Delaney.
One possible reaction to this rejection of corporate money in politics: So what?
"You know in some ways the commitment for a presidential candidate not to take PAC money is a really weak commitment, because presidential candidates generally don't take much PAC money," said Jennifer Victor, a political scientist at George Mason University.
Case in point: Sen. Marco Rubio, R-Fla., was the leading recipient of PAC money in the 2016 presidential contest. His total from all PACs — not just the corporate sector — came to barely 2 percent of his campaign receipts.
But for Democratic candidates, the pledge is about more than dollars. Muller said that when End Citizens United polled voters after the midterm elections, "independent voters told us that cleaning up Washington and cleaning up corruption was the number one reason why they chose who they voted for. So I think these presidential candidates understand that."
Corporate PACs, of course, don't appreciate the symbolism. The president of the D.C.-based National Association of Business PACs, Catherine McDaniel, pointed out in an email to NPR that corporate PACs are funded by employees, not from corporate accounts. She said "some candidates" might consider the boycott good politics, but "we think it does a great disservice to all those Americans who work hard for a living and want to make a positive contribution to our democracy."
The candidates' commitments go well beyond refusing corporate PAC money. Warren and Castro say they won't take funds from any PAC, apparently shutting out PACs representing unions, environmental groups and other progressive stalwarts. Warren, Harris, and Gillibrand will just say no to money from federally registered lobbyists, and say they don't want support from superPACs either. That's hard to control, though, because superPACs by law cannot coordinate with candidates. Booker is on board with the no-lobbyist-dollars pledge.
What's happening now is at least the start of a pivot. More than half of the newly-elected House Democrats say they don't want corporate PAC contributions. In effect, they're moving beyond traditional fundraising — the business of combing Rolodexes to build big-dollar fundraising networks — and branding themselves to court the grassroots donors who give small contributions online.
But Taryn Rosenkranz, founder of the digital fundraising firm New Blue Interactive, said the impact of grassroots donors could be diminished, due to the size of the Democratic Party's presidential field.
"The grassroots is going to be, you know, much like the electorate: spread thin across so many different candidates," she said. Her conclusion: Small-donor giving could provide an ad-hoc straw poll as the race takes shape; but over the long haul, it won't concentrate enough cash to fully fund a White House run.