Sen. Mark Udall [D-CO]

U.S. Senator, Colorado

These labels come from the Political Spectrum statistical analysis that we have carried out. The statistical analysis puts members of Congress on a scale based on patterns of bill sponsorship, and is blind to party affiliation and the content of bills. From there, we have somewhat arbitrarily divided the Members of Congress into far-left/right, rank-and-file, and moderate (i.e. centrist). For each party, the most extreme 23% of Members of Congress are labeled far-left or -right. The most centrist 30% (i.e. those closest to the other party) are labeled moderate. The remaining 47% are labeled as rank-and-file.

To compute the leader-follower score for Udall, we make a table that lists all other Members of Congress. Each row has the number bills sponsored by Udall and cosponsored by the other Member of Congress divided by the number of bills sponsored by the other Member of Congress and cosponsored by Udall.

This is a measure of who is following who. The higher the number, the more times others are cosponsoring Udall's bills without Udall returning the favor. We then take the mean of (the logorithms of) these ratios. Thanks to Joe Barillari for the idea.