Kerry's nomination is the only one expected from the White House this afternoon, although other cabinet members, including Secretary of Defense Leon Panetta, are expected to leave the administration in the coming weeks.
An earlier possible State Department nominee, U.S. Ambassador to the United Nations Susan Rice, withdrew from consideration for the position when Republicans began to mobilize against her. At issue was Rice's involvement in the Obama administration's response to the deadly Sept. 11 attack on the U.S. consulate in Benghazi, Libya.
Kerry's nomination will place a respected statesman and party elder in a high-profile cabinet position. But it will also create an opening in the Senate.
Sen. Scott Brown, the moderate Republican who lost his bid for re-election in November to consumer advocate Elizabeth Warren, is expected to consider a run for Kerry's seat.