Martin's fortunes declined dramatically in his last years. Alcoholism, illness, and poverty weighted heavily on Martin, taking their toll as he aged. By the mid-1820s, he was subsisting on a special tax imposed on Maryland lawyers solely for his personal support. Eventually, he was taken in by Aaron Burr, whom he had defended at this disgraced ex-vice president's 1807 trial for treason. By this time, detestation of Thomas Jefferson, his one-time decentralist ally, led Martin to embrace the Federalist Party, in apparent repudiation of everything he had argued for so strenuously. Paralysis, which had struck in 1819, forced him to retire as Maryland's attorney general in 1822.