BOSTON (AP) -- Delegates to the Massachusetts Republican convention have strongly endorsed Charlie Baker for governor, but there remains some question on whether he will face a primary election challenge from tea party member Mark Fisher.

Baker was announced as the winner of the convention, but it was unclear if Fisher, a Shrewsbury business owner, met the 15 percent threshold he needed under party rules to win a spot on the September GOP ballot against Baker.

Baker served in the administrations of two former Republican governors and later served as chief executive of Harvard Pilgrim Health Care. He was the party's 2010 nominee, losing in the general election to Democratic Gov. Deval Patrick.

Republicans also endorsed several other candidates at the convention, including former state Rep. Karyn Polito for lieutenant governor and Brian Herr, a Hopkinton selectman, for U.S. Senate.