A New Jersey native hailing from Summit, Elmendorf graduated from Trinity College in 1982 and began his career as a field organizer on the Mondale for President campaign. He was later chief of staff for U.S. Representative Dennis Eckart, and a staff aide to Senator Brock Adams. Elmendorf joined Gephardt's staff in 1992 and became chief of staff in 1997. He managed the floor for House Democrats and designed the Democratic Caucus’ strategic response to issues including the impeachment of President Bill Clinton, the Clinton 1993 economic program, the Clinton effort to reform health care in 1994, NAFTA, the 1997 Balanced Budget Act, McCain-Feingold campaign finance reform and the Iraq war resolution. While in the leader’s office, he was named every year by Roll Call newspaper as one of the 50 most powerful staff people on Capitol Hill. He managed four of Gephardt's successful campaigns for Democratic leader and organized the congressman’s outside political activities at the Democratic Congressional Campaign Committee and at Gephardt's political action committee. Elmendorf was elected by the members of the House of Representatives as a minority officer of the House in the 105th, 106th and 107th Congress, entitling him to the same privileges as former members of the House. He served as chief of staff and senior advisor for Gephardt’s 2004 Democratic presidential campaign. In 2004, as deputy campaign manager for Kerry’s 2004 presidential bid, Elmendorf was the primary campaign liaison to U.S. senators, members of Congress, governors and mayors. He also supervised the field operations in 21 states and was on the strategic team involved in overall campaign planning and worked in the campaign’s outreach to constituency groups and organized labor. In November 2011, Elmendorf was included on The New Republic's list of Washington's most powerful, least famous people.
2006 elections
In January 2006, Elmendorf was criticized vehemently by some left-wing Democratic bloggers when he was quoted in a Washington Post story as saying, "The bloggers and online donors represent an important resource for the party, but they are not representative of the majority you need to win elections. The trick will be to harness their energy and their money without looking like you are a captive of the activist left." Markos Moulitsas, head of the Daily Kos blog, replied: "Here's notice, any Democrat associated with Elmendorf will be outed. The netroots can then decide for itself whether it wants to provide some of that energy and money to that candidate. There's nothing 'extreme left' with demanding Democrats act like Democrats, no matter how much these out-of-touch and self-important beltway insiders think it is." Also in 2006, Elmendorf gave his support to U.S. Senator Joe Lieberman's independent re-election bid after Lieberman lost the Democratic primary. Elmendorf was listed on Lieberman's campaign Web site as part of the "national chapter" of "Dems for Joe."