President Obama raised a combined $43.6 million in April for his campaign and the Democratic Party.
Obama's campaign says 400,000 donors contributed last month, including 169,000 who donated for the first time. Obama raised about $53 million in April.
Campaign manager Jim Messina told supporters in a web video released early Wednesday that the November election will be close because of "historic challenges" and that so-called special interests are dumping millions into anti-Obama ads.
Presidential campaigns and super PACs have until midnight Sunday to file their fundraising reports with the Federal Election Commission.
