In 1960, Pell won the seat of retiring U.S. Senator Theodore Francis Green, defeating former Governor Dennis J. Roberts and former Governor and U.S. Senator J. Howard McGrath in the Democratic primary, and former Rhode Island Republican Party Chairman Raoul Archambault in the general election.

Despite being called "the least electable man in America" by John F. Kennedy because of his many odd habits and beliefs, Pell proved a durable politician.
 He won reelection five times, including victories over Ruth M. Briggs (1966), John Chafee (1972), James G. Reynolds (1978), Barbara Leonard (1984), and Claudine Schneider (1990).

Often considered by his opponents to be too easygoing, Pell demonstrated his effectiveness as a campaigner.
 During his first campaign, when he was accused of carpetbagging, Pell published newspaper advertisements featuring a photograph of his grand-uncle Duncan Pell, who had served as Lieutenant Governor of Rhode Island during the 1860s, thus demonstrating Pell's association with the state.
When Briggs called him a "creampuff" during their 1966 campaign, Pell turned that to his advantage and mocked Briggs by obtaining an endorsement from a local baker's union.

During his first campaign, Pell also used his foreign experience to great advantage, impressing some largely immigrant audiences in person and on the radio by campaigning in their native languages.
In 1960, Pell won the seat of retiring U.S. Senator Theodore Francis Green, defeating former Governor Dennis J. Roberts and former Governor and U.S. Senator J. Howard McGrath in the Democratic primary, and former Rhode Island Republican Party Chairman Raoul Archambault in the general election.
Despite being called "the least electable man in America" by John F. Kennedy because of his many odd habits and beliefs, Pell proved a durable politician.  He won reelection five times, including victories over Ruth M. Briggs (1966), John Chafee (1972), James G. Reynolds (1978), Barbara Leonard (1984), and Claudine Schneider (1990).
Often considered by his opponents to be too easygoing, Pell demonstrated his effectiveness as a campaigner.  During his first campaign, when he was accused of carpetbagging, Pell published newspaper advertisements featuring a photograph of his grand-uncle Duncan Pell, who had served as Lieutenant Governor of Rhode Island during the 1860s, thus demonstrating Pell's association with the state. When Briggs called him a "creampuff" during their 1966 campaign, Pell turned that to his advantage and mocked Briggs by obtaining an endorsement from a local baker's union.
During his first campaign, Pell also used his foreign experience to great advantage, impressing some largely immigrant audiences in person and on the radio by campaigning in their native languages.
Claiborne Pell