In 1972, the Democratic gubernatorial runner-up from December 1971, former state senator J. Bennett Johnston, Jr., of Shreveport challenged Ellender for renomination.
Ellender was expected to defeat Johnston, but the veteran senator died in July during the primary campaign and left Johnston the de facto Democratic nominee.
Nearly 10 percent of Democratic voters, however, still voted for the deceased Ellender.

Johnston became the Democratic nominee in a manner somewhat reminiscent of how Ellender had won the Senate seat in 1936 after the death of Governor Oscar K. Allen.
Johnston easily defeated the Republican candidate, Ben C. Toledano, a prominent attorney from New Orleans who later became a conservative columnist, and former Governor John McKeithen, a Democrat running as an Independent in the general election because he had not been able to qualify for the primary ballot, given the timing of Ellender's death.

The Ellender family endorsed McKeithen in the 1972 general election because of resentment over Johnston's entry into the race against Ellender.

Ellender's immediate successor was not Johnston but Elaine S. Edwards, first wife of Governor Edwin Edwards, who was appointed to fill his seat from August 1, 1972, to November 13, 1972.
Six days after the election, Johnston was appointed to finish Ellender's remaining term to gain a seniority advantage over other freshman senators.
In 1972, the Democratic gubernatorial runner-up from December 1971, former state senator J. Bennett Johnston, Jr., of Shreveport challenged Ellender for renomination. Ellender was expected to defeat Johnston, but the veteran senator died in July during the primary campaign and left Johnston the de facto Democratic nominee. Nearly 10 percent of Democratic voters, however, still voted for the deceased Ellender.
Johnston became the Democratic nominee in a manner somewhat reminiscent of how Ellender had won the Senate seat in 1936 after the death of Governor Oscar K. Allen. Johnston easily defeated the Republican candidate, Ben C. Toledano, a prominent attorney from New Orleans who later became a conservative columnist, and former Governor John McKeithen, a Democrat running as an Independent in the general election because he had not been able to qualify for the primary ballot, given the timing of Ellender's death.
The Ellender family endorsed McKeithen in the 1972 general election because of resentment over Johnston's entry into the race against Ellender.
Ellender's immediate successor was not Johnston but Elaine S. Edwards, first wife of Governor Edwin Edwards, who was appointed to fill his seat from August 1, 1972, to November 13, 1972. Six days after the election, Johnston was appointed to finish Ellender's remaining term to gain a seniority advantage over other freshman senators.
Allen J. Ellender