In 2004, Deutsch declared his candidacy for the Democratic nomination for the Senate seat being vacated in 2005 by retiring Democratic Senator Bob Graham. Although Deutsch consistently led opinion polls in the Miami-Fort Lauderdale metropolitan area, and had the largest amount of cash on hand for most of the race, he lagged in statewide opinion polls behind rival Betty Castor, whose fundraising dramatically accelerated during the summer of 2004 with the help of EMILY's List, which contributed close to $4.5 million in television and advertising dollars. The Castor campaign was accused of inappropriate coordination with EMILY's List, and a lawsuit was filed with the Federal Elections Commission.