Ross began his political career in
Canyon County, serving as county commissioner from 1915 to 1921. He moved east to
Bannock County and served as mayor of
Pocatello from 1922 to 1930, and won the Democratic gubernatorial nomination in
1928. Although Ross nearly tripled the Democratic vote total of his predecessor Asher Wilson, thanks to the recent demise of the Idaho
Progressive Party, he was defeated by the
Republican incumbent
H. C. Baldridge. Ross won the nomination again in
1930, winning the open seat against Republican John McMurray. His wife, Edna, was a natural politician and a great asset to Ross. She was often referred to as "Governor Edna" while he held that office. He was reelected in
1932 and
1934, becoming the first in Idaho to win three elections for governor. During his tenure, Ross was viewed as the chief proponent of
Franklin D. Roosevelt's
New Deal policies in Idaho. Even so, his own beliefs more closely mirrored the agrarian
populism of earlier Democrats such as
William Jennings Bryan. The first
sales tax in Idaho was enacted in 1935 with Ross' support. A famous line used against Ross by sales tax opponents was "A Penny for Benny." A driver's license law was instituted and legislation was initiated which would make liquor sales regulated through state distributors. Instead of pursuing a fourth term, Ross ran for
U.S. Senate in 1936 but was defeated its
dean, Republican
William Borah. Opponents also used the following poem against him: "Benny got our penny/Benny got our goat/We'll get our Benny/When we go to vote." The sales tax was repealed after a statewide
referendum in 1936, but later returned in 1965. Ross ran for governor a fifth time in
1938, defeating incumbent
Barzilla Clark in the primary, but lost to state
Republican Party chairman
C. A. Bottolfsen in the general election. After the loss, "Cowboy Ben" retired from public life. He is referred to as "Founding Father" of the Idaho Farm Bureau Federation and was looked to as a champion of the
Idaho Democratic Party. ==Personal life==