Bernie Sanders had his biggest single day yet for donations following the Iowa caucus on Monday, which he narrowly lost to Hillary Clinton. The campaign reported raising $3 million since Monday night, The Washington Post reports. Four in 10 of those donors had not previously contributed to Sanders' campaign, according to Sanders communications director Michael Briggs."It's been our best day ever," he said. In January, Sanders raked in $20 million, primarily from donations averaging $27 each.