WASHINGTON—As the 119th Congress takes office, the leaders of the Senate Republican Conference and Senate Democratic Caucus have unveiled their proposed committee assignments, which will heavily influence the policy agenda of the Senate for the next two years. Standing committees—which are permanent committees—in the Senate are the first bodies to review legislation and take a leading role in preparing it for votes on the Senate floor. The chairmen of these committees wield significant power over this process. The committees also hold oversight hearings and consider the president’s nominees to various executive branch positions. Opposition from a committee chairman often prevents a bill or nomination from ever receiving a vote. Hence, senators wrangle to secure prestigious committee assignments that affect key policy areas, so as to accrue more influence in the political process….