In 1915, Katō was selected as a member of the House of Peers by Imperial command.
He became president of the conservative Kenseikai political party in the following year, whose policies he greatly influenced with his opposition to the genrō, support of the constitution and support for extension of popular suffrage.

Katō was appointed Prime Minister of Japan from 1924 until his death in early 1926.
His cabinet was nicknamed the "Goken Sanpa Naikaku" (Cabinet based on the three pro-Constitution factions), which, despite its coalition nature, was able to enact significant legislation.
In 1925, Katō had the General Election Law enacted, which extended the vote to all male citizens over the age of 25.
He also ratified the Peace Preservation Law, which suppressed leftist political organizations, and concluded the Soviet–Japanese Basic Convention.
He also initiated universal military service.
Katō strove to reduce government spending, but also suffered considerable personal criticism for his family links with Mitsubishi.
In 1915, Katō was selected as a member of the House of Peers by Imperial command. He became president of the conservative Kenseikai political party in the following year, whose policies he greatly influenced with his opposition to the genrō, support of the constitution and support for extension of popular suffrage.
Katō was appointed Prime Minister of Japan from 1924 until his death in early 1926. His cabinet was nicknamed the "Goken Sanpa Naikaku" (Cabinet based on the three pro-Constitution factions), which, despite its coalition nature, was able to enact significant legislation. In 1925, Katō had the General Election Law enacted, which extended the vote to all male citizens over the age of 25. He also ratified the Peace Preservation Law, which suppressed leftist political organizations, and concluded the Soviet–Japanese Basic Convention. He also initiated universal military service. Katō strove to reduce government spending, but also suffered considerable personal criticism for his family links with Mitsubishi.
Katō Takaaki