Shortridge was born in Mount Pleasant, Iowa and moved to California as a child with his family, who settled in San Jose in 1875.

[2] He lost the 1914 U.S. Senate Republican primary to veteran congressman Joseph R. Knowland, who was defeated in the general election by James D. Phelan.

Shortridge was elected to the U.S. Senate in 1920, riding Warren G. Harding's post World War I "Return to Normalcy" campaign.

Shortridge became a prominent voice for racist anti-Japanese forces in California, declaring that a child of Japanese immigrants would regard "himself or herself as a native of Japan.

[4] Even some senators who wanted to favor northern and western European immigrants found Shortridge's anti-Japanese position unnecessary.