St. John Mildmay was one of 15 children, who, according to an account of 1804, were ‘all very handsome, and bear a strong resemblance to each other’.
At the 1820 general election St. John Mildmay was returned again for Winchester unopposed. His hustings speech contained no political professions, though he dissented by implication from his Grenvillite colleague’s support for the Six Acts.
At the 1826 general election he offered again for Winchester and at his unopposed return declared his unequivocal support for Catholic relief, observing that ‘it was very easy to raise the cry of "No Popery", but they might just as well say "No Chinese"’. Responding to comments about the paucity of his contributions to debate, he urged the electors not to forget ‘the not unimportant body of listeners’ and insisted that he gave ‘many hours of anxious attention’ to the arguments deployed.
At the 1830 general election he was again returned unopposed. On the hustings he predicted that in the new Parliament ‘there would be less occasion than ever to oppose the measures of government’.
The contest in Winchester at the ensuing general election was not aimed at St. John Mildmay, and his profession of support for the reform bill in its entirety was warmly received. But he embroiled himself in controversy by giving a plumper to the anti-reform candidate, the son of his former colleague East. His effigy was burnt in the street and he was called to account for himself at a meeting, 4 May, when he confessed that his conduct had been dictated by a long standing electoral agreement. For this he was publicly censured, following which he ‘left the city within an hour of the meeting, evidently in very dejected spirits’, though his subsequent address of thanks ascribed his hurried departure to an anxiety to assist the cause of reform in Somerset, where he had privately promised Edward Sanford* ‘to secure for you every vote I can influence’.
St. John Mildmay voted for the second reading of the revised reform bill, 17 Dec. 1831, again gave general support to its details, and divided for its third reading, 22 Mar. 1832. He was listed as absent ‘in country’ for the division on the motion for an address asking the king to appoint only ministers who would carry the bill unimpaired, 10 May, around which time he was reported to be canvassing Winchester in anticipation of a dissolution.
St. John Mildmay died in May 1845 at his mother’s seat at Dogmersfield. The cause was tetanus, which set in after his leg was broken in an altercation with an angry mare, with whose foal his pony had tangled while he was riding in the park. An obituarist praised his ‘urbane, charitable and kind’ character and cited the length of the tenancies on his Somerset estate as evidence of his generosity.
