Trapp at the same period plunged into politics as a Tory and a high churchman. He assisted
Henry Sacheverell at his trial in 1709 and 1710, and on Sacheverell's recommendation became in April 1710 his successor in the lectureship at
Newington, Surrey. The preface to a tract on the trial was written by him, and in September 1710 he vindicated Sacheverell's noisy progress into exile in an anonymous pamphlet. Another anonymous pamphlet by Trapp was called
The true genuine Tory Address and the true genuine Whig Address set one against another, 1710. From 1714 to 1722 he held by the gift of the
Earl of Peterborough the rectory of
Dauntsey in
Wiltshire, and through the interest of William Lancaster he obtained in 1715 the lectureship at the church of
St. Martin-in-the-Fields, Westminster. The governors of
St. Bartholomew's Hospital elected Trapp on 20 April 1722 as vicar of the united parishes of Christ Church, Newgate Street, and St. Leonard, Foster Lane, and in 1733 he was presented by Lord Bolingbroke to the rectory of
Harlington in
Middlesex. He also held lectureships in several London churches, and became president of
Sion College. He died of
pleurisy at Harlington on 22 November 1747. and was buried on the north side of the entrance into the chancel, upon the north wall of which is a monument; another, the cost of which was borne by the parishioners, is on the east wall of the chancel of Newgate church. The books in Trapp's library at Warwick Lane, London, to which Sacheverell's library had been added, and those at Harlington, with his son's collections, passed to
Robert Palk. ==Controversy==