Background: Robert Arthur Talbot Gascoyne-Cecil, 3rd Marquess of Salisbury,  (3 February 1830 - 22 August 1903), styled Lord Robert Cecil before 1865 and Viscount Cranborne from June 1865 until April 1868, was a British statesman of the Conservative Party, serving as Prime Minister three times for a total of over thirteen years. He was the last Prime Minister to head his full administration from the House of Lords. Lord Robert Cecil was first elected to the House of Commons in 1854 and served as Secretary of State for India in Lord Derby's Conservative government from 1866 until his resignation in 1867 over its introduction of Benjamin Disraeli's Reform Bill that extended the suffrage to working-class men. In 1868 upon the death of his father, Cecil was elevated to the House of Lords.
Context: He entered the House of Commons as a Conservative on 22 August 1853, as MP for Stamford in Lincolnshire. He retained this seat until entering the peerage and it was not contested during his time as its representative. In his election address he opposed secular education and "ultramontane" interference with the Church of England which was "at variance with the fundamental principles of our constitution". He would oppose "any such tampering with our representative system as shall disturb the reciprocal powers on which the stability of our constitution rests". In 1867, after his brother Eustace complained of being addressed by constituents in a hotel, Cecil responded: "A hotel infested by influential constituents is worse than one infested by bugs. It's a pity you can't carry around a powder insecticide to get rid of vermin of that kind".  In December 1856 Cecil began publishing articles for the Saturday Review, to which he contributed anonymously for the next nine years. From 1861 to 1864 he published 422 articles in it; in total the weekly published 608 of his articles. The Quarterly Review was the foremost intellectual journal of the age and of the twenty-six issues published between spring 1860 and summer 1866, Cecil had anonymous articles in all but three of them. He also wrote lead articles for the Tory daily newspaper the Standard. In 1859 Cecil was a founding co-editor of Bentley's Quarterly Review, with John Douglas Cook and Rev. William Scott; but it closed after four issues.  Salisbury criticised the foreign policy of Lord John Russell, claiming he was "always being willing to sacrifice anything for peace... colleagues, principles, pledges... a portentous mixture of bounce and baseness... dauntless to the weak, timid and cringing to the strong". The lessons to be learnt from Russell's foreign policy, Salisbury believed, were that he should not listen to the opposition or the press otherwise "we are to be governed... by a set of weathercocks, delicately poised, warranted to indicate with unnerving accuracy every variation in public feeling". Secondly: "No one dreams of conducting national affairs with the principles which are prescribed to individuals. The meek and poor-spirited among nations are not to be blessed, and the common sense of Christendom has always prescribed for national policy principles diametrically opposed to those that are laid down in the Sermon on the Mount". Thirdly: "The assemblies that meet in Westminster have no jurisdiction over the affairs of other nations. Neither they nor the Executive, except in plain defiance of international law, can interfere [in the internal affairs of other countries]... It is not a dignified position for a Great Power to occupy, to be pointed out as the busybody of Christendom". Finally, Britain should not threaten other countries unless prepared to back this up by force: "A willingness to fight is the point d'appui of diplomacy, just as much as a readiness to go to court is the starting point of a lawyer's letter. It is merely courting dishonour, and inviting humiliation for the men of peace to use the habitual language of the men of war".
Question: How was he able to keep his seat so long?. Whats the answer?