France was elected to the Maryland State Senate in 1906, serving until 1908. He left the Senate in 1908 to engage in the field of finance. He served as the secretary to the medical and surgical faculty of Maryland from 1916–1917. After a short time out of politics, France re-entered the political arena in 1916 and was elected to the United States Senate. During the 65th Congress, he served in the Senate as the chairman of the Committee on Public Health and National Quarantine. France attempted to introduce an amendment to the Sedition Act of 1918 that would have ensured limited free speech protections, but the amendment was defeated, and France would remark that the legislation was criminal, repressive, and characteristic of the Dark Ages. France warned in March 1920 that "Republican liberals" would split off the Republican Party to form the "Anti-Prohibition Party". France introduced a joint resolution in the same month asking that dissenters imprisoned during World War I be pardoned. He was an unsuccessful candidate for re-election in 1922, losing his seat to Democratic rival William Cabell Bruce. Following his defeat, France became President of the Republic International Corporation and also resumed the practice of medicine in Port Deposit. France also joined the Freemasons during this time. France opposed Herbert Hoover in Republican primaries during the Presidential campaign of 1932. He was giving a speech at the Republican Convention in Chicago when the microphone malfunctioned, leaving France continuing his speech while the sound system was repaired. Although he won some contests, few delegates were selected in the primaries and France was heavily defeated at the convention. When Senator Phillips Lee Goldsborough announced his retirement from the Senate in 1934, France attempted to win his seat. He was unsuccessful in the election of 1934, losing to Democratic rival George L. P. Radcliffe. He died in Port Deposit five years later, and is buried in Hopewell Cemetery, near the city.
France was the first U.S. Senator to visit Russia after the Russian Revolution, and consistently advocated cordial relations with the Soviet Union. In 1921 after having been sent to Russia to study economic conditions there, he met with Russian officials, including Lenin, to assist in the release of Marguerite Harrison, an American journalist and convicted spy. Lenin wrote in a letter to Georgy Chicherin: The letter went on to relate that Marguerite Harrison was the sister-in-law of the Governor of Maryland and that Senator France's re-election was put in jeopardy by her incarceration. France attracted controversy in the United States by accusing Colonel Edward W. Ryan of the American Red Cross of fomenting the Kronstadt rebellion.
Civil rights
France spoke at a 1920 meeting of the NAACP to support the enactment of the Dyer Anti-Lynching Bill. France fought against voter disenfranchisement, and proposed an amendment to a railroad bill so that black train passengers paying a first-class fare could get first-class accommodations.
