On October 9, 1939, following the death of Senator Logan, Chandler resigned as governor, elevating Lieutenant Governor Keen Johnson to the governorship.
The following day, Johnson appointed Chandler to Logan's vacated seat in the Senate.
In a special election to fill the remainder of the unexpired term, Chandler then first defeated Charles R. Farnsley in the Democratic primary and Republican Walter B. Smith by a vote of 561,151 to 401,812 in the November 5, 1940, general election.
Although he never forgave Roosevelt for backing Barkley in the 1938 senatorial primary, he generally supported the Roosevelt administration except for parts of the New Deal.

Chandler's mentor, Harry F. Byrd, led a group of Southern conservatives in the Senate, and through Byrd's influence, Chandler was appointed to the Committee on Military Affairs.
In 1943, he was part of a five-person delegation from the Military Affairs Committee that traveled the world, inspecting US military bases.
He vociferously disagreed with Roosevelt's decision to prioritize the European Theatre in World War II over the pacific Theatre.

Chandler upset many in the black community by voting against an anti-lynching bill soon after taking office.
The bill levied fines against local governments and individual government officials in counties in which illegal lynchings had occurred.
Of his vote against the bill, Chandler remarked, "I am against lynching by anybody and of anybody, black or white, but the present bill carries penalties on local officials and local subdivisions which I think are too severe."
The bill passed in the House of Representatives but died in the Senate.
Later, Chandler joined with Southern senators in opposing the repeal of poll taxes, which had been long used as a mechanism to prevent blacks from voting.

At the expiration of his partial term in 1942, Chandler faced a challenge from former ally John Y. Brown, Sr.
in the Democratic primary.
As a result of his votes on the anti-lynching bill and the poll tax repeal, the Louisville chapter of the National Association for the Advancement of Colored People worked against his re-election effort.
During the campaign, Brown accused Chandler of abusing his power, including of having a swimming pool installed at his home, in violation of the federal rationing provisions that had been implemented during World War II.
Chandler invited the Truman Committee to investigate the installation of the pool and no violations of the federal rationing provisions were found.
Chandler went on to defeat Brown and was easily re-elected in the general election over Republican Richard J. Colbert.

Chandler believed that he had enough support at the 1944 Democratic National Convention to be nominated as Roosevelt's running mate for that year's presidential election.
The support failed to materialize, however, after the Kentucky delegation, Earle C. Clements in particular, refused to back his nomination.
The convention nominated Harry Truman as Roosevelt's running mate.
Truman became president upon Roosevelt's death in 1945, and Chandler never forgave Clements for costing him the chance to be US President.
On October 9, 1939, following the death of Senator Logan, Chandler resigned as governor, elevating Lieutenant Governor Keen Johnson to the governorship. The following day, Johnson appointed Chandler to Logan's vacated seat in the Senate. In a special election to fill the remainder of the unexpired term, Chandler then first defeated Charles R. Farnsley in the Democratic primary and Republican Walter B. Smith by a vote of 561,151 to 401,812 in the November 5, 1940, general election. Although he never forgave Roosevelt for backing Barkley in the 1938 senatorial primary, he generally supported the Roosevelt administration except for parts of the New Deal.
Chandler's mentor, Harry F. Byrd, led a group of Southern conservatives in the Senate, and through Byrd's influence, Chandler was appointed to the Committee on Military Affairs. In 1943, he was part of a five-person delegation from the Military Affairs Committee that traveled the world, inspecting US military bases. He vociferously disagreed with Roosevelt's decision to prioritize the European Theatre in World War II over the pacific Theatre.
Chandler upset many in the black community by voting against an anti-lynching bill soon after taking office. The bill levied fines against local governments and individual government officials in counties in which illegal lynchings had occurred. Of his vote against the bill, Chandler remarked, "I am against lynching by anybody and of anybody, black or white, but the present bill carries penalties on local officials and local subdivisions which I think are too severe." The bill passed in the House of Representatives but died in the Senate. Later, Chandler joined with Southern senators in opposing the repeal of poll taxes, which had been long used as a mechanism to prevent blacks from voting.
At the expiration of his partial term in 1942, Chandler faced a challenge from former ally John Y. Brown, Sr. in the Democratic primary. As a result of his votes on the anti-lynching bill and the poll tax repeal, the Louisville chapter of the National Association for the Advancement of Colored People worked against his re-election effort. During the campaign, Brown accused Chandler of abusing his power, including of having a swimming pool installed at his home, in violation of the federal rationing provisions that had been implemented during World War II. Chandler invited the Truman Committee to investigate the installation of the pool and no violations of the federal rationing provisions were found. Chandler went on to defeat Brown and was easily re-elected in the general election over Republican Richard J. Colbert.
Chandler believed that he had enough support at the 1944 Democratic National Convention to be nominated as Roosevelt's running mate for that year's presidential election. The support failed to materialize, however, after the Kentucky delegation, Earle C. Clements in particular, refused to back his nomination. The convention nominated Harry Truman as Roosevelt's running mate. Truman became president upon Roosevelt's death in 1945, and Chandler never forgave Clements for costing him the chance to be US President.
Happy Chandler