“…Incumbents can be electorally vulnerable depending on their legislative positions while in office. If senators take legislative positions out of step with their constituents, they will get lower vote shares, even losing reelection (Erikson & Wright, 2000;Canes-Wrone, Brady, & Cogan, 2002;Carson & Engstrom, 2005;Ansolabehere & Jones, 2010;Carson, Koger, Lebo, & Young, 2010;Kassow & Finocchiaro, 2011). In this sense, it is reasonable to believe that the probability that the incumbent decides to retire is largely structured by the probability of electoral success.…”