As his elder half-brother Wilmot was mentally unstable, Vaughan was the effective heir to his father’s interest in Cardiganshire and elsewhere. On the death of his uncle John in 1795, he was to have been put up on the family interest at Berwick: Sir Lawrence Palk, his brother-in-law, writing to the Duke of Portland, 2 Aug. 1795, assured him that ‘Mr Vaughan inherits a most respectful attachment to your Grace and a steady determination to support the measures of government in this arduous crisis’.
Vaughan did not cut a figure in Parliament, where he made no known speech, unless it is true that he spoke on militia affairs in 1804. In general, he supported administration; but after Pitt had requested his attendance by circular, 27 Sept. 1797, and Vaughan’s father had taken this opportunity to press his claims for an English peerage, which were spurned, Vaughan voted in a minority of 15 against Pitt’s tax proposals, 4 Dec. 1797. He did not appear in subsequent minority lists and resumed his military career.
Vaughan was by 1818 deeper in debt and less often in Cardiganshire than ever and, rather than face another contest, gave up his seat. It had in fact been disposed of in his absence, as part of a compromise at the county by-election of 1816, when Vaughan was ‘tossed on the shelf’.
