Thomas Andrew Daschle is an American politician and lobbyist who represented South Dakota in the United States Senate from 1987 to 2005. A member of the Democratic Party, he led the Senate Democratic Caucus during the final ten years of his tenure, during which time he served as Senate Minority Leader and Majority Leader.

The Democratic Caucus of the United States Senate, sometimes referred to as the Democratic Conference, is the formal organization of all senators who are part of the Democratic Party in the United States Senate. For the makeup of the 118th Congress, the caucus additionally includes three independent senators who caucus with the Democrats, bringing the current total to 51 members. The central organizational front for Democrats in the Senate, its primary function is communicating the party's message to all of its members under a single banner. The present chair of the Senate Democratic Caucus is Chuck Schumer of New York.