The receptions are more of a rally than the catered affairs at a wealthy donor's home that are typical of political fundraisers. Sanders has instead raised the bulk of his funds online, with an active Internet presence aimed at recruiting smaller givers. The kinds of crowds we're drawing, the kinds of small donations that are coming into the campaign, the kind of volunteer organizations that we're putting together has gone a lot faster than I thought it would," Sanders said Thursday in an interview on the NPR show "On Point. Yet Sanders' success in the past three months underscores a concern among Clinton supporters, namely that her financial edge is declining as she spends money at a rapid clip, while his upstart bid remains lean and with enough money to keep competing deep into the primaries. A 2,600-word missive he sent in April 2014 features a section, highlighted by the use of capital letters, railing against the influence of billionaire donors in political campaigns. "THE STRUGGLE THAT WE'RE ENGAGED IN RIGHT NOW IS WHETHER WE CAN PREVENT THIS COUNTRY FROM MOVING TO AN OLIGARCHIC FORM OF SOCIETY IN WHICH VIRTUALLY ALL ECONOMIC AND POLITICAL POWER RESTS WITH A HANDFUL OF BILLIONAIRES," he wrote. After announcing a $24 million haul in the early evening, his campaign used social media sites to appeal for more money before the midnight deadline.