BOSTON – Massachusetts voters weary from one of the nation’s costliest and most divisive U.S. Senate races are all but certain to find themselves thrown back into another tumultuous election now that President Barack Obama has nominated Sen. John Kerry for secretary of state.

If confirmed by the Senate, as expected, Democrat Kerry would have to resign the seat he’s held for nearly three decades, meaning a special election that will be the state’s third Senate contest since 2010.

Jockeying already is well under way. The big question is whether Republican Sen. Scott Brown will go for the seat after losing his last month to Democratic Elizabeth Warren.