Hynicka moved to the camp of
George B. Cox, and took responsibility for maintaining Cox's voter card file. This contained records on every voter in Cincinnati, including where they worked, which church they belonged to and any scandals in which they had been involved. Hynicka became the most powerful of Cox's supporters. He headed Cincinnati's influential Republican Central Committee of ward and township captains and managed allocation of the 2,000 political patronage jobs in the city. By the start of the 1890s Hynicka, Cox and
Garry Herrmann dominated Cincinnati politics. In 1897 they lost a mayoral election campaign in which the Democrat
Gustav Tafel promised to clean up the city. Various scandals emerged after the Democrats took office. One involved Hynicka using his office as clerk of the police court to earn bribes of $150–$200 a week. The Republican candidate
Julius Fleischmann was elected in 1900 and reelected in 1903. Hynicka was elected treasurer of Hamilton County in 1903, his only elective office. In October 1905 the Cox machine was attacked by
William Howard Taft in a speech linked to President
Theodore Roosevelt's drive to eliminate corruption in business and politics. In 1911 Cox announced "I am retiring. I hope my enemies will find other targets". When Cox retired Hynicka became leader of the Republican party in Hamilton county. Hynicka and Herrmann agreed to reorganize the Republican Advisory Committee without Cox at the request of
Charles Phelps Taft, the president's brother. On 2 April 1912 Hynicka announced that he had withdrawn from politics to devote himself to his business interests. Cox and Herrmann had already made similar announcements. Later Hynicka was chosen to represent Ohio in the
Republican National Committee, holding this position until 1924, when he was succeeded by Maurice Mashke of
Cleveland. In the 1920 elections the Republicans won the White House by a landslide. In Cincinnati, however, Hynicka's candidates were less successful, indicating that his power was waning. A letter from
Warren G. Harding of 4 October 1921 said "... I should not grieve if Hynicka should be overturned in Hamilton County, but I do not subscribe to the theory that the way to overturning is to put the Republican party out of power in the municipality of Cincinnati." In 1926 Hynicka retired from his position as chairman of the Hamilton county executive and central committee of the Republican organization. ==Other interests==