They may not look alike, but Senate twins vote alike. Senators from 22 states had composite scores within 5 percentage points of each other, in National Journal's 2010 vote ratings.
Here are the top 10 pairs of Senate twins -- home-state senators who have composite scores within 1 point of each other.
Former Sen. Blanche Lincoln (D) and Sen. Mark Pryor (D) have the same composite scores. Lincoln and Pryor have the same score on foreign-policy issues but differ by 1 point on both economic and social issues.