In the early months of 1975, the Senate struggled to resolve two contested elections. In New Hampshire, Republican Louis Wyman claimed a 355-vote margin over Democrat John Durkin. But, after two recounts, Wyman's margin stood at only two votes. The Senate investigated the election for six months before declaring the seat vacant. Durkin easily won the special election.

The second protracted 1975 contest involved the Oklahoma seat to which Republican Henry Bellmon was seeking reelection. Bellmon had won by a margin of 3,800 votes. His Democratic challenger, Ed Edmondson, a 20-year House veteran, called for a new election. He argued that voting machines had malfunctioned in one county, thereby inflating Bellmon's totals. The state supreme court, however, unanimously supported Bellmon, who then received an election certificate.

Mindful that the Senate had taken up a similar contest four years earlier, Edmondson asked the body to review his case. The Senate agreed. It seated Bellmon "without prejudice" to any later findings that the Rules Committee might present.

The Rules Committee at that time was swamped with the hand-counting of hundreds of disputed Wyman-Durkin ballots. It put off its Bellmon-Edmondson review until November. On December 15, the committee's Democratic majority dutifully supported Edmondson's call for a new election. The panel concluded that it was impossible to "determine who would have won the election had the [voting-machine irregularities] not occurred."

The full Senate took up the committee report in March 1976—14 months after the start of the term. As it did with Wyman and Durkin, the Senate accorded Edmondson floor privileges while the case was under review. Attorneys for both men sat in the rear of the Chamber. On display were two Oklahoma voting machines: one that operated properly; and one that did not.

Senator Bellmon asserted that the Senate would be setting a bad precedent if it declared his seat vacant. There were no charges of misconduct against either candidate and Edmondson had not requested a recount. It was simply a close election. Throwing out the results could lead the losers of all close elections to burden the Senate with their appeals.

On March 4, 1976, the Senate finally resolved the case. As a senior member of the Agriculture and Budget committees, Bellmon earned considerable support among Democrats. Nine of them, with six in reserve, joined all Republicans on a 47-to-46 vote to confirm his victory.

After his vigorous battle to secure a second term, the 59-year-old Bellmon surprised supporters in 1980 by announcing that he would not seek a third term. Explaining his decision, he quoted Rhode Island Senator John Pastore's memorable line: "It is better for you to leave while friends urge you to stay than to stay so long that friends urge you to leave."