But on 31 May 1661 Titus, who is described as groom of the bedchamber, was made keeper of Deal Castle (ib. 1660–1, p. 598). In 1666, during the Dutch war, he was captain of a company in the lord-admiral's regiment of foot (2 July) and colonel of a regiment of Kentish militia (ib. 1665–6, pp. 280, 487, 510). On 3 Feb. 1670 he was returned to parliament for Loswithiel, in February 1679 for Hertfordshire, in August 1679 and in February 1681 for Huntingdonshire. During the excitement of the popish plot and the exclusion bill Titus became one of the leaders of the House of Commons. He was one of the first to attack Danby (Grey, Debates, vi. 352, 362, vii. 135), urged the removal of Lauderdale from the king's councils, and in 1680 that of Halifax (ib. vii. 196, viii. 22, 282). No one believed more entirely in the plot or was more eager against papists. He was one of the managers of Lord Stafford's trial, and did not hesitate to denounce the judges when they showed any doubts of the evidence for the plot or discouraged protestant petitioners. Titus was not eloquent, but he was a vigorous speaker with a gift of humorous illustration which made his speeches effective. Lawrence Hyde, who was incapable of jesting himself, once complained that Titus had made the house sport, to which Titus retorted that things were not necessarily serious because they were dull. A good specimen of his style is the speech on moderation in dealing with papists, which called forth Hyde's criticism (Grey, vii. 400). But his most famous speech was against the limitation which Charles offered to impose upon a catholic sovereign, rather than pass the bill for excluding his brother from the throne. Titus argued with great effect that when a sovereign was once upon the throne, it would be practically impossible to maintain these restrictions. ‘To accept of expedients to secure the protestant religion, after such a king had mounted the throne, would be as strange as if there were a lion in the lobby, and we should vote that we would rather secure ourselves by letting him in and chaining him than by keeping him out’ (ib. viii. 279; Chandler, Debates, ii. 93). The illustration is versified in Bramston's ‘Art of Politics’ (1729).
After the dissolution of the parliament of 1681 Titus kept aloof from the conspiracies in which some of the whig leaders engaged, though in July 1683, when the Rye House plot was discovered, it was rumoured that a warrant was out against him (Luttrell, Diary, i. 266). Five years later, when James II was striving to win over the nonconformists, Titus was one of the persons to whom he applied. He approved of the repeal of the penal laws, but by February 1688 declared that he would have no more to do with James, and that he was convinced that the design of the government was to bring in popery (Mackintosh, James II, p. 210). Nevertheless on 6 July 1688 he accepted a seat in the privy council, allured, according to Macaulay, by the honour offered him and the hope of obtaining a large sum due to him from the crown (Hist. of England, i. 534, people's edit.). He was present at the last council meeting held by James after his return from Feversham, but he had no hesitation in transferring his allegiance to William (Bramston, Autobiography, p. 340; Diary of Henry, Earl of Clarendon, ed. Singer, ii. 180, 228).
His compliance with James had destroyed his former popularity, but he succeeded in getting returned to the parliament of 1690 for Ludlow (Luttrell, Diary, ii. 311). His speeches had lost their effectiveness, but sometimes a flash of his old humour appeared in them. He was zealous for triennial parliaments, and urged the passing of the triennial bill, even though it had originated in the lords. At the same time he owned it was natural that the commons should dislike to have the lords prescribe to them times when to meet and when to be dissolved. ‘St. Paul desired to be dissolved; but if any of his friends had set him a day, he would not have taken it well of them’ (Grey, Debates, x. 373, cf. x. 298, 308). At the general election of 1695 Titus stood for Huntingdonshire, and his defeat then terminated his political career (Luttrell, iii. 544). He died in December 1704, and was buried at Bushey (Le Neve, Monumenta Anglicana, 1700–15, p. 92). Titus left three daughters.
The grant of an addition to his coat-of-arms made to Titus in 1665 enumerates, among his services, that ‘by his pen and practices against the then usurper, Oliver, he vigorously endeavoured the destruction of that tyrant and his government.’ This probably refers to the fact that Titus claimed the authorship of ‘Killing no Murder.’ Evelyn in his ‘Diary’ under 2 April 1669 attributes the pamphlet to Titus. On the other hand, Titus, when referring to it in his correspondence with Clarendon at the time of its publication, makes no claim for himself (Cal. Clarendon Papers, iii. 397). Moreover, Sexby before his death confessed to having written it (Thurloe, vi. 560), and internal evidence supports his statement. Titus, however, was very intimate with