Sen. Lamar Alexander abruptly announced in a letter to his colleagues on Tuesday that he is stepping down from his influential leadership post on the GOP side of the Senate Conference Committee after playing a central role in shaping Republican policy against President Obama. Alexander said the surprising move was motivated by his desire to “work for results on the issues I care most about,” and to foster consensus—something his partisan job as the GOP No. 3 in the Senate didn’t allow. By abandoning the conference committee, Alexander ensures he won’t become the powerful party whip in the next Congress. Sen. John Thune from South Dakota is next in line for Alexander’s spot on the conference committee.