Smart Politics finds that Russ Feingold’s (D) official entrance into the 2016 U.S. Senate race puts him on an unusual pathway back to the nation’s upper legislative chamber.

“Over the last half-century only two U.S. Senators have returned to the chamber after losing their seat at the ballot box – Ohio Democrat Howard Metzenbaum in 1976 and Washington Republican Slade Gorton in 1988. No other Senator accomplished this feat since 1956.”

However, from “the beginning of direct elections in 1913 until the mid-1950s, such political comebacks were much more common with 14 defeated ex-U.S. Senators winning back a seat in the chamber including one who accomplished the feat twice: Kentucky Republican John Cooper in 1952 and 1956 (after losses in 1948 and 1954 respectively).”

Former Sen. Russ Feingold (D-WI) announced that he will run to reclaim the U.S. Senate seat he lost five years ago to Ron Johnson (R), “fulfilling the hopes of Democrats who have been pushing for the liberal to return to the political arena,” the AP reports.

In the video announcement filmed inside his home near Madison, Feingold said his “desire to serve is stronger than ever” and that he wants to fight to “bring back to the U.S. Senate strong independence, bipartisanship and honesty.”