Davidson entered parliament unopposed for
Hemel Hempstead in a 1920 by-election and became
Parliamentary Private Secretary to Bonar Law, then Lord Privy Seal and Leader of the House of Commons. The latter resigned on the grounds of ill health in May 1921, when Davidson became PPS to Stanley Baldwin, who by then had become
President of the Board of Trade. Stanley Baldwin was chosen to succeed Bonar Law as Prime Minister over the claims of
Lord Curzon. In his biography of Davidson in the
Dictionary of National Biography,
Robert Blake writes that Davidson's role in the appointment of Baldwin remains a puzzle.
Lord Stamfordham,
George V's private secretary, sounded out Davidson on Bonar Law's wishes for his successor. Bonar Law, now gravely ill, asked not to be involved, but it was apparent that he favoured Baldwin although he could not overlook the claims of party grandee, Curzon. In 1954, a memorandum was found in the
Royal Archives that had obviously been dictated by Davidson and clearly argued for the claims of Baldwin over Curzon. The note had been handed over to Stamfordham by
Sir Ronald Waterhouse, another of Bonar Law's secretaries, at the same time as his official resignation as Prime Minister. Stamfordham had noted on the memorandum that it "practically expressed the views of Mr. Bonar Law". According to Blake, there was nothing in the memorandum to substantiate that claim. Davidson subsequently said that he had dictated the note after being asked by Stamfordham about the opinion of back-bench MP's. However, Blake argued, "In any case, the result [Baldwin as Bonar Law's successor] was affected only marginally. The King's decision was firmly based on his own good sense and the powerful arguments of
Balfour against the choice of a
peer as prime minister". and effectively continued as the prime minister's private secretary. However, he lost his seat in parliament at the
general election of December 1923, but regained it already in the
general election in October the following year. Baldwin once again formed an administration after the brief first-ever
1924 Labour government, and made Davidson
Parliamentary and Financial Secretary to the Admiralty. In this post he was forced to deal with cuts in naval expenditure proposed by the
Chancellor of the Exchequer,
Winston Churchill, especially regarding the construction of new cruisers. He served as deputy chief civil commissioner during the
general strike of 1926, with responsibility for publicity. He also managed the short-lived
British Gazette during the strike and arranged for the broadcasting of official bulletins. According to Blake, Davidson "left a lasting imprint on the organization of the party, including the creation of the Research Department, and many of the changes attributed to his successor,
Neville Chamberlain, were in fact his". However, Davidson came under criticism after the defeat at the
1929 general election and resigned in 1930. He was chairman of the Indian States inquiry committee and travelled to
India in 1932 and was made a member of the joint select committee whose proposals resulted in the
Government of India Act 1935. He declined the
governorship of Bombay. He invited Joachim von Ribbentrop to meet with Stanley Baldwin for the first time in Westminster to discuss Hitler's ideas about equality in armaments. He remained Chancellor of the Duchy of Lancaster when Baldwin became Prime Minister for the third time in 1935, although he was never a member of the cabinet. He was succeeded as MP by his wife,
Frances, Viscountess Davidson (see below). ==Later career, 1937–1970==