Denney served one term in the
Delaware House of Representatives, during the 1905-06 session, and was chosen as Speaker. He was the personal secretary to Delaware
U.S. Senator Harry A. Richardson from 1907 until 1913. In 1920 he was elected Governor of Delaware, defeating the
Democratic Party candidate, Andrew J. Lynch, a
Georgetown lawyer. The 1921 session saw a renewed struggle over public education. In the previous session, the far reaching, innovative legislation known as the "School Code of 1919" was enacted. This act completely reworked public education in Delaware by empowering a state superintendent to set standards, consolidated hundreds of tiny local school districts into countywide districts, established a 180-day school year, and provided for a County board of education to appropriate funding through the county property tax. It was hotly debated then, and only narrowly passed. The opponents were poised to repeal the whole legislation in 1921, but through much effort, proponents managed a compromise, the "School Law of 1921". It lessened the standards, including the 180-day school year, but most importantly moved the funding from the counties to the state through an income tax. To manage that funding, it replaced the county boards of education with a State board of education and a State School Tax Commissioner. The whole effort was a personal mission of
Pierre S. du Pont. He was prominent among those who persuasively argued its passage, not only in the General Assembly, but in hundreds of small gatherings around the state. And it was his personal $5,000,000 contribution, given over 20 years, which made possible much of the reconstruction of suitable buildings to meet the standards established. Denney was at the center of controversy over a series of appointments that came to be known as "the Dirty Deal". In 1921 the term of respected Chancellor Charles M. Curtis was due to expire. Denney could easily have reappointed him, but instead chose to nominate
Josiah O. Wolcott to the post. Wolcott was thought to want to be chancellor, but had the added advantage of being a Democratic U.S. Senator, whose appointment as chancellor would create the opportunity for Denney to appoint a Republican to the U.S. Senate. The scenario created weeks of clamor, with the Delaware Bar demanding the reappointment of Curtis and Wolcott saying he would refuse the appointment. Denney persisted though, and Wolcott was appointed, resigning his U.S. Senate seat. Then Denney dropped a bombshell by appointing his friend and Republican Party leader,
T. Coleman du Pont, to the U.S. Senate seat. The press exploded, convinced that du Pont, one of the wealthiest men in the country, had bought the position for himself. Du Pont was eventually punished by being defeated in the
U.S. Senate election of 1922, but Wolcott served a long and distinguished career as chancellor. After leaving office, Denney served as acting secretary of state for Delaware in 1931, commissioner of the State Motor Vehicle Commission in 1940, and was the state librarian from 1941 to 1948. He was also a member of the Republican State Committee from 1920 to 1953, and served as chair from 1926 to 1928. He was chair of the 1922 and 1928 Republican State Conventions, and served as a delegate to the
1908,
1924, and
1928 Republican National Conventions. ==Death and legacy==