Former U.S. Senator John E. Sununu (R-N.H.) says he is considering running for Senate in New Hampshire in 2026, held by the retiring Jeanne Shaheen (D), who defeated him in 2008. If he were to run, he would have to face another former U.S. Senator, Scott Brown (R-Mass.), who was defeated by Elizabeth Warren (D) in 2012. If Sununu entered, these two wouldn’t be the only Senators running for Senate again, as former Ohio Senator Sherrod Brown (D) is running after being defeated by Bernie Moreno (R) in 2024.

Excluding Scott Brown’s and Sherrod Brown’s current candidacies, Ballotpedia has found that at least 24 Senators have run again in 26 elections after leaving office since 1976. Of these 24, 12 were Republicans, 10 were Democrats, and two were independents. On average, these Senators ran seven years after leaving office, one year longer than a regular Senate term of six years. Some notable Senators who ran again include former Vice President Walter Mondale (D), former Attorney General Jeff Sessions (R), and former Presidential candidate Eugene McCarthy (D).

In 26 elections, a Senator lost the general election 13 times (50%), lost the primary five times (19%), withdrew from the primary four times (15%), and won four times (15%).

Of 26 elections, there have been instances where Senators ran against each other. Two elections were rematches: Wisconsin in 2016, when Ron Johnson (R) defeated Russ Feingold (D), and Minnesota in 1996, when Paul Wellstone (D) defeated Rudy Boschwitz (R). Additionally, in 2014, two Senators ran for the nomination of New Hampshire’s Senate seat. Scott Brown (R) won the Republican nomination, defeating nine other candidates, including former Senator Bob Smith (R).  

If John Sununu ran, 2026 would see the most former Senators running since 2012 and 2014, when three former Senators ran in both of those cycles. If Sununu does not run, 2026 would be tied with 1976, 1994, 2010, and 2016, when two Senators each ran during those election cycles.