Why is harding regarded as the worst president in American History?

Answer 1

http://www.historycentral.com/bio/presidents/harding.html

Warren Harding has consistently been rated as the worst President of the United States. His failings were only recognized after his term was over. During his Presidency, he was well-liked. His major election slogan had been "A Return to Normalcy." His Presidency saw the ascendancy of business interest in government. The Treasury Secretary was the multi-millionaire industrialist, Andrew Mellon.

After his death, the extent of the scandals occurring during his administration became known. The Attorney General was responsible for widespread graft, leading to a criminal trial. The head of the Veteran's Administration looted millions of dollars. The Secretary of the Interior was guilty of accepting a bribe to lease a US naval reserves to private oil companies. This became known as the Tea Pot Dome scandal.

Answer 2

From Wikipedia:

Due to multiple scandals involving others in his administration, Harding is ranked by most scholars as one of the least successful Presidents.

Warren Gamaliel Harding (November 2, 1865 - August 2, 1923) was an American politician and the 29th President of the United States, from 1921 to 1923, when he became the sixth president to die in office. A Republican from the U.S. state of Ohio, Harding was an influential newspaper publisher with a commanding presence and a flair for public speaking. He served in the Ohio Senate (1899-1903) and later as lieutenant governor of Ohio (1903-1905) and as a U.S. Senator (1915-1921). His political leanings were conservative, which enabled him to become the compromise choice at the 1920 Republican National Convention. In the 1920 election, he defeated his Democratic opponent James M. Cox in a landslide, 60.36 % to 34.19%. As president he appointed a strong cabinet, led by Secretary of State Charles Evans Hughes, Secretary of the Treasury Andrew Mellon and Secretary of Commerce Herbert Hoover. However some other appointments proved to be corrupt. In foreign affairs Harding liquidated World War I, and led the way to world naval disarmament at the Washington Naval Conference of 1921-22. In domestic affairs he ended the postwar depression, stabilized inflation, cut wartime taxes, and opened a decade of prosperity.

Harding died in San Francisco, California, 27 months into his term, at age 57 from a heart attack.

Just to give you something to think about.

From The Nation.com:

Generally speaking, Reeves says James Buchanan, our 15th president, usually earns the worst ever distinction, as "a confused, indecisive president, who may have made the Civil War inevitable by trying to appease or negotiate with the South."

Good Luck....