Jennings twice sought the Democratic nomination for the United States Senate, losing in 1934 and 1964.

The couple had to keep the marriage a secret since at the time it was considered socially improper for a teacher to be married.

[8] Jennings served as a justice of the Supreme Court of Arizona from December 12, 1960, to August 5, 1964.

[9] In 1964, he resigned from the Court to run for the Senate again, this time for the seat held by Barry Goldwater.

[10] Governor Paul Fannin appointed Edward W. Scruggs to fill the vacancy created by Jennings resignation.