He was elected to the California State Senate, the Legislature's upper house, in 1966; initially for a two-year term.

The U.S. Supreme Court had ruled that state legislatures must reapportion their upper houses on the basis of population; in the process in California, the even-numbered districts elected their senators for full four-year terms in 1966.

He and George L. Brown of Colorado became the first two African Americans elected to the office of lieutenant governor since Oscar Dunn did so in Louisiana during Reconstruction.

Franchetti later said that the source of the rumor was a Los Angeles Times reporter, who called the Justice Department trying to confirm its authenticity.

[7] The report was passed to Curb's office with the rumor part erased, after which it moved to broadcaster Bill Stout, who announced it as fact on Los Angeles radio station KNX (AM) and its CBS affiliates.

[9] In 1980, two years after losing the lieutenant governorship, Dymally ran for Congress in District 31, against former U.S. representative Mark W. Hannaford (who had served two terms in a nearby district) and 18-year incumbent Charles H. Wilson, who had been reprimanded by his U.S. House colleagues for financial misconduct in the Koreagate scandal.

Dymally won the primary with 49% of the vote, to 24% for Hannaford and just 15% for Wilson; he went on to defeat Republican Don Grimshaw in the general election, 64%-36%.

In 1983 Dymally joined with seven other U.S. representatives to sponsor a resolution to impeach Ronald Reagan over his sudden and unexpected invasion of Grenada.