"It was foolish for anyone in the Democratic establishment not to take Bernie seriously before [Wednesday]," said Neil Sroka, communications director for the progressive PAC Democracy for America. "But it's absolutely laughable to not take him seriously after the fundraising haul he was able to bring in, in a certain day." Sroka, like Petkanas, emphasized the power of in having more than 225,000 donors on Day One, especially when those supporters can turn into volunteers who can knock on doors, man phone banks or sign on for recurring donations. He also warned the Democratic Party, which largely underestimated Sanders's appeal to progressives in 2016, against making the same mistake."More than anything, the surprise that might exist about the numbers Bernie was able to post [Tuesday] is indicative of a chattering class in Washington that doesn't understand the Democratic base and hasn't understood it in years," said Sroka, who was part of a group that urged Sen. Elizabeth Warren to run in 2016. That loyal base outside of Washington -- the quarter of a million people who donated to Sanders right out of the gate -- proved Tuesday that they're still hanging on.