Complex sentence: Roy L. Elson (born c.1930) is an American politician from Arizona, and a onetime aide and protege of longtime Senator Carl Hayden (D-AZ), is perhaps best known as the Democratic nominee for the U.S. Senate in 1964 and 1968.
Split into simpler sentences: Roy L. Elson (born c.1930) is an American politician from Arizona, and a onetime aide and protege of longtime U.S. Senator Carl Hayden (D-AZ). He is perhaps best known as the Democratic nominee for the U.S. Senate from Arizona in 1964 and 1968.