What is Cosponsorship?
Cosponsorship is the voluntary addition of a congressperson's name to a bill before the Congress. Rule 22 of the Rules of the House of Representatives dictates that any legislator may request that their name be added to a bill, starting with the time of a bill's initial introduction to the Congress and ending with the time that the bill is passed from a committee onto the House floor. The effect of having one's name added to a bill is to indicate support for it.
How Common is Cosponsorship?
Cosponsorship is common in the Congress. Over half of all bills in the 99th Congress had at least one cosponsor (Wilson and Young 1997). In the 105th Congress of 1997-1998, the number of cosponsors for any given bill varied from zero to well over two hundred. Cosponsorship is also common as an individual practice. Individual congresspeople tended to cosponsor over a hundred bills in the 105th Congress, with again much variation: Rep. Lloyd Doggett of Texas cosponsored only three bills, while Rep. Martin Frost, also of Texas, cosponsored 804 bills, or one out of every six bills.
Cosponsorship: A History
Official cosponsorship is a relatively new practice in the Congress. For the House, the reported date of cosponsorship's beginning is 1967, with a liberalization of rules to allow unlimited cosponsorship in 1978 (Congressional Record 1967: 10708-10712; Congressional Record 1978: 34929-34931).
While these dates mark the legalization of cosponsorship of a single bill, previous House sessions saw similar tactics that worked their way around legal prohibitions. "Multiple introduction," the submission of identical bills with different resolution numbers and different principal sponsors, served as the functional equivalent of modern-day cosponsorship for some time before legalization (Congressional Record 1967: 10712). The willingness of legislators to wholly reintroduce legislation in order to register their support for it indicates that cosponsorship, or its equivalent, has long played an important role in the legislative process.
Does Cosponsorship Matter?
Cosponsorship has a strong reputation on and around Capital Hill for its supposed impact on legislative outcomes. Comments made by Rep. William Colmer of Mississippi in support of the bill that formalized cosponsorship reflect that reputation:
