If selected, he would have to give up his seat in the House and any hope of supplanting John Boehner as speaker.
Not that Dodd, his closest friend in the Senate, is supplanting Kennedy.
While earning millions, reality-TV stars are supplanting the role of movie stars in some ways.
c.1300, "to trip up, overthrow, defeat, dispossess," from Old French supplanter "to trip up, overthrow," from Latin supplantare "trip up, overthrow," from sub "under" + planta "sole of the foot" (see plant (n.)). Meaning "replace one thing with another" first recorded 1670s. Interesting sense evolution parallel in Hebrew akabh "he beguiled," from akebh "heel."