Clinton’s ancestors, established in Warwickshire since the reign of Henry I, were raised to the peerage in 1299, and first represented that county in Parliament in 1301. His grandfather acquired property in Lincolnshire by marriage in 1531, becoming one of the county magnates with electoral influence at Boston and Grimsby.
Returned to the first Jacobean Parliament for Lincolnshire, Clinton, a strong puritan, was appointed on the opening day of business to both committees for grievances raised by Sir Robert Wroth I* and Sir Edward Montagu* (23 Mar. 1604), and to another to confirm the liberties of the subject (29 March).
At the summer assizes of 1605 Clinton was accused by the father of Sir Edward Tyrwhitt* of malversation of coat and conduct money and the arbitrary dismissal of a high constable, allegedly in order ‘to make himself great and powerful, to sway matters according to his own will and mind and, if he might, to bear rule himself alone in the said county’. The judges ordered the high constable’s re-instatement; but proceedings against Clinton in Star Chamber came to nothing.
Clinton neither attended nor gave a proxy for the Addled Parliament in 1614, though he was one of the peers who signed a petition against the creation of baronets.
