Democrats spent over $1 billion on failed presidential bids

Warren faces challenge from Sanders in home state despite financial backing

Two of this cycle’s top megadonors are running for president

South Carolina donors give the greatest amount to Biden as Sanders cuts into the lead

Super PACs backing Warren and Klobuchar won’t disclose donors until long after Nevada

Castro, Booker have highest proportion of contributions from Iowa women

Big-dollar donors helped Deval Patrick lay groundwork for presidential campaign