Patrick, who is a Democrat, would appoint a temporary senator in the interim. He has indicated that he will follow the precedent he set in 2009 when, after the death of Senator Edward M. Kennedy '54-'56, he appointed veteran Kennedy aide Paul G. Kirk Jr. '60 to fill the seat on the condition that Kirk not run in the special election.

Outgoing U.S. Senator Scott Brown, who in his election night concession speech declared that “defeat is only temporary,” appears poised to run again. Last month he lost the seat he had won in a 2010 special election to former Harvard Law School professor Elizabeth Warren.

On the Democratic side, three congressmen from local districts—Stephen F. Lynch, Michael E. Capuano, and Edward J. Markey—have all expressed interest in running, with Markey emerging as the early favorite for the Democratic nomination. Also potentially in the fray is Edward M. Kennedy Jr., the son of the late longtime U.S. Senator.

Both parties would hold primaries six weeks before the election.

This summer's special election would be the second special election in Massachusetts in three years, as well as the third statewide election in that time. Brown, who ran in Senate elections in both 2010 and 2012, is expected to be the clear frontrunner if he runs again this summer, according to Republican political strategist Todd Domke. Brown has cash leftover from the costly November election, a campaign team and strategy in place, and high favorability ratings in the state.

Domke said he thinks a potential Brown campaign could begin running advertisements as early as February.

Warren, who will become the Massachusetts senior U.S. Senator as a freshman in Congress, congratulated Kerry on Tuesday, but made no mention of Brown or the now likely special election.

—Staff Writer Matthew Q. Clarida can be reached at clarida@college.harvard.edu.

—Staff Writer Nicholas P. Fandos can be reached at nicholasfandos@college.harvard.edu.

This article has been revised to reflect the following correction:

CORRECTION: Dec. 23

An earlier version of this article incorrectly stated that outgoing U.S. Senator Scott Brown ran in three elections in Massachusetts in the past three years. In fact, Brown ran in two Senate elections in the state during that time and is expected to compete in a third.