Having come so close, Wilson refused to accept defeat, and he continued to challenge Leach's victory. The Republicans supporting Wilson maintained that Leach won on the basis of votes bought by the Democrats in Vernon Parish, especially in the predominantly black section of Leesville known as "The Crossing." Wilson's challenge led to 22 persons pleading guilty to vote-buying on Leach's behalf in 1979 court litigation. Two others were convicted on similar charges. Leach himself was acquitted on November 3, 1979, by a federal district court in Lake Charles on bribery charges stemming from the 1978 general election. The U.S. Justice Department later dropped similar charges against Leach dealing with the 1978 primary.
The U.S. House appointed a special subcommittee of the Administration Committee to investigate Wilson's charges against Leach. On December 20, 1979, the subcommittee voted 2-1 on party lines to dismiss Wilson's petition, which charged that voters were paid on Leach's behalf in sufficient numbers to alter the outcome of the general election. Two Democrats, John Burton and Joseph Minish, voted to dismiss, but the Republican Robert Badham favored continuance. Wilson claimed that he lost the general election because 440 votes were bought in Vernon Parish, but the Democratic majority on the subcommittee said that the available evidence showed only 66 votes were bought, a number insufficient to alter the outcome.
In February 1980, the House Administration Committee voted 11-7 to reject Wilson's call for the unseating of Leach. The vote mirrored party alignment, with all Democrats voting to dismiss, and each Republican favoring continuance of the investigation. Finally, on March 4, 1980, the full House voted 241-153 to drop Wilson's challenge. Leach's Democratic colleagues from Louisiana, Jerry Huckaby, Gillis William Long, John Breaux, and Lindy Boggs all voted to dismiss, but the three Louisiana Republican congressmen, David C. Treen, W. Henson Moore, and Robert L. "Bob" Livingston abstained. A handful of Republicans voted with Leach, and a handful of Democrats sided with Wilson's allegations.
Rebuffed by Congress, Wilson announced on April 30, 1980, Statehood Day in Louisiana, that he would challenge Leach in the 1980 nonpartisan blanket primary. A Shreveport Journal poll showed Wilson with a slim lead at the time in a potential re-run of a race against Leach. There was, however, a large bloc of uncommitted voters. Wilson said that he expected to raise and spend $500,000 for the second race because national Republicans had again targeted the Fourth District as one of 35 in the nation where the GOP stood a chance of winning a Democratic seat.
Wilson said in his announcement for the 1980 race that he had gone "as far as we could in the Congress with the vote-fraud problems. I think it's now to be left up to the voters of the Fourth District to decide if there was voter fraud in the election. That will happen this fall. ... The Democrats have allowed convicted felons to serve in Congress. The Democrats wouldn't pay any attention to our forty names of bought votes. Then on top of that, Brilab [a congressional scandal]. That makes me think that people are fed up with wthat kind of thing in Congress."
In addition to Wilson and Leach, Roemer also ran again in 1980. So did State Representative Forrest Dunn of Shreveport, a furniture store owner known for fiscal conservatism and frank expression of ideas who had supported President Ford over Jimmy Carter in 1976. Dunn's entry was believed to have attracted the same kinds of voters who might have otherwise preferred the Republican Wilson.
Another entry was the moderate-to-liberal and highly ambitious Democratic state Senator Foster L. Campbell, Jr., of Bossier Parish, a former educator who had succeeded the conservative Harold Montgomery in the District 36 Senate seat in 1976. Near the end of the first phase of the campaign, Campbell had questioned Roemer's commitment to the Second Amendment.
Former Democratic State Senator Cecil Kay Carter, Jr., who served Caddo Parish from 1972 to 1976, threw his hat into the ring as well.
In the September 1980 primary, Leach led with 35,847 votes (28.9 percent). Roemer was second with 33,049 (26.8 percent). Wilson finished third with 29,992 (24.4 percent). Campbell polled 14,666 votes (11.9 percent), and Dunn received 8,208 ballots (6.7 percent). Carter ran last with 1,329 (1 percent). As predicted by some Republicans, Dunn polled more than enough votes to keep Wilson from a first- or second-place primary finish, presuming that Dunn voters' second choice in most cases would have been Wilson.
After he was eliminated from the race, Wilson endorsed Roemer.
Ultimately, however, Roemer defeated Leach in an all-Democratic "general election" under Louisiana law, held simultaneously with the Reagan-Carter presidential race. Wilson, despite the vote-buying allegations that had ruined his chances in 1978, hence failed to gain a spot in the general election.
Wilson's defeat was no anomaly. He was mistaken if he thought that voters would reward him in 1980 on the basis of his having been the victim of election theft in 1978. In other situations too, voters have rejected candidates who were defeated by questionable means in previous elections. Some see them as "sore losers". Other voters may not want to be reminded of past election chicanery. Still other voters oppose the candidate for reasons of their own, both personal and policy-related.
Wilson's congressional defeats ended his political career. He was twice divorced. Soon his health broke, and he died of cancer. Survivors included four children from his first marriage to the former Joan "Joannie" Quinby of Vivian: two sons, Hamilton Paul Wilson, II, and James Michael Wilson, both then of Vivian, and two daughters, Amanda Wilson Murry of Vivian and Melissa Wilson Brown, then of Washington, D.C.; his mother Lola Wilson, three sisters Jean Brown, Mimi Cochran, and Peggy Wilson, and four grandchildren. Wilson's second wife was the former Shreveport newswoman Ann Beebe.
Services were held in the Vivian United Methodist Church. Wilson was cremated.