set rates higher than necessary to protect home industries. U.S. senator In June 1908, Governor Cummins ran in the Republican primary for the U.S. Senate seat held by William B. Allison, who was seeking a record seventh term. Cummins was accused of breaking an earlier promise not to challenge Allison, and lost by over 12,000 votes. However, Senator Allison died on August 4, 1908, two months after the primary and before the Iowa General Assembly chose among the primary winners. In November 1908, a second Republican primary was held, which Cummins won decisively. Later that month and again two months later, in January 1909, Cummins was appointed by the Iowa General Assembly over Democratic rival Claude R. Porter. He served as U.S. senator from Iowa for 18 years, from 1908 until his death in 1926. He served as president pro tempore of the U.S. Senate between 1919 and 1925. He also chaired the Senate Judiciary Committee and the Committee on Interstate Commerce. Cummins generally supported President Woodrow Wilson's initiatives to regulate business, and authored a clause of the Sherman Antitrust Act. Although Cummins voted in favor of the 1917 United States declaration of war on Germany when Wilson requested it, he sided most often with his party than with Wilson on other foreign policy issues, opposing the arming of merchant ships in early 1917 and U.S. membership in a League of Nations in 1919 and 1920. It was as Interstate Commerce Commission chair that Cummins sponsored the Esch-Cummins Act of 1920, establishing the conditions for the return of the railroads to private control after their government operation during World War I. Labor activists complained that the bill perpetuated harsh limits on collective bargaining, including provisions making it a crime to encourage a railroad strike, in the absence of a wartime emergency. It symbolized Cummins' postwar break with the progressive movement, which would ultimately contribute to his defeat. Pursuit of the presidency In January 1912, Cummins announced his intention to run for the Republican presidential nomination. He was considered as a candidate at the 1912 Republican National Convention. However, during the turmoil following the walkout of Theodore Roosevelt's supporters, Cummins's name was not placed in the presidential ballot. In the national election, Cummins supported Roosevelt rather than Taft, even though he opposed Roosevelt's creation of a third party. In 1916, Cummins again ran for the Republican presidential nomination at the 1916