There are many subcommittees in the U.S. Senate. On the third of February, 2021, the committees were reorganized to reflect the new Democratic majority in the Senate. Since then, some subcommittees have also been reorganized, and some have not. What is the process used by the respective party caucuses/conferences to decide who shall serve in which subcommittees?
What is the process used by the respective party caucuses/conferences to decide who shall serve in which subcommittees?
In About the Senate Committee System, "Each party assigns its own members to committees, and each committee distributes its members among its subcommittees."
Committee membership is determined by the process given below.
From Senate Committees,
The committee assignment process in the Senate is guided by Senate rules along with party rules and practices. Most new members arrive at the Senate with a "wish list" of committee assignments. They recognize that appointment to committees with a special impact on the interests of their states and regions can promote their own legislative effectiveness. For Senate party leaders, the committee appointment process offers a means of promoting party discipline through the granting or withholding of desired assignments.
Until the mid-19th century, the Senate made committee appointments either by vote of the full body or decision of its presiding officer. The first method proved inordinately time consuming; the second provoked controversy and dissatisfaction. Finally, in 1846, members agreed to a procedure under which both political parties within the Senate would submit for the full body's approval a slate of members to fill the various committee seats. This new plan fostered development of Senate party conferences (Democrats informally use the designation "caucus"). Independents and members of third parties have received committee assignments through one or the other of the major party conferences.
In the practice of recent years, party conferences convene before the start of each new Congress to elect leaders and determine committee assignments. Each party conference appoints a "committee on committees" to prepare a roster of members it wishes named to the party's specifically allotted committee seats. The percentage of a party's representation within the Senate determines the percentage of seats it will gain on each committee, although exact numbers are subject to negotiation between party floor leaders.
Party conference rules provide that each newly elected senator may choose a committee assignment before any other newly elected member is allowed to make a second committee choice. New senators make their selections according to a priority system that gives first choice to those who have previously served in the Senate, then to those with prior House service, and finally to those who served as their state's governor. All other new members have their order of choice determined by random drawing.