Ending months of speculation, City Councilor Tito Jackson will jump into this year’s mayoral race, vowing a vigorous campaign against his friend and former ally, Mayor Martin J. Walsh.

The 41-year-old Roxbury councilor, who will announce his mayoral candidacy at 2 p.m. Thursday at Dudley Square’s Haley House, is setting the stage for an uphill but competitive contest later this year. Although the field of candidates is not yet set, Jackson is hoping to become the first viable African-American candidate on the November mayoral ballot in more than three decades — since the candidacy of former state representative Mel King.


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