Thirty-five years before Thursday's upcoming start of televised House hearings on the Jan. 6, 2021, attack on the U.S. Capitol, the United States turned its eyes to congressional hearings on the Iran-contra scandal in the Reagan administration.

The scandal involved secret arms sales to Iran — despite an arms embargo — with the proceeds illegally used to support the "contras," rebels fighting the leftist government in Nicaragua. The outcome tarnished President Ronald Reagan's image as the "Teflon president" who never got stuck with blame.

The House select committee hearings on the U.S. Capitol invasion by supporters of former president Donald Trump are expected to be the most-watched hearings since the 1973 Senate Watergate inquiry that led to the resignation of President Richard M. Nixon. The panel predicts bombshell disclosures not only about the attack itself but about events leading up to and following it. The Iran-contra hearings similarly uncovered a complex web of illicit actions that undermined U.S. democracy.

In "Iran-Gate," as news media called it, Reagan officials illegally sold missiles and other weapons to Iran for its war against Iraq in an effort to improve relations and free seven American hostages held in Lebanon by the Iranian-backed terrorist group Hezbollah. Then, working with the Central Intelligence Agency, officials funneled the profits into military aid to the Nicaraguan rebels despite a congressional ban on such aid.

Disclosure of the arms-peddling in late 1986 by the Lebanese newspaper Al-Shiraa set off a firestorm. Reagan fired several top national security officials but denied any arms-for-hostages dealings. In November, his monthly approval rating suffered "the largest single drop for any U.S. president in history" up to that date, to 46% from 67% in October, a New York Times/CBS poll wrote.

In early 1987, the presidentially appointed Tower Commission confirmed the secret dealings. In a televised speech in March 1987, Reagan responded: "A few months ago, I told the American people I did not trade arms for hostages. My heart and my best intentions still tell me that's true, but the facts and the evidence tell me it is not." He added that "as angry as I may be about activities undertaken without my knowledge, I am still accountable for those activities."

Congress already was moving to conduct what The Washington Post wrote "could be the most significant three months of televised congressional hearings since Watergate." The joint Senate-House committee was chaired by Sen. Daniel Inouye, D-Hawaii, who had been a member of the Senate Watergate committee. One House member of the committee was Rep. Dick Cheney, R-Wyo., the father of Rep. Liz Cheney, R-Wyo., who co-chairs the House committee investigating the Jan. 6 attack. Unlike his daughter, who has criticized former president Donald Trump for opposing the hearings, the senior Cheney praised Reagan. "It is important, I think, for people to know that the president has indeed cooperated fully with our investigation," he said.

The hearings began May 5, 1987, in the same Senate Caucus Room as the Watergate hearings 14 years earlier. Retired Air Force Major Gen. Richard Secord revealed that $3.5 million of the $18 million profit (equal to about $45 million now) from the 1985-86 sales of U.S. arms to Iran was used to finance the airlift of military equipment to the Nicaraguan rebels. Secord's covert operations company Enterprise handled the transactions.

During Secord's afternoon testimony, some TV networks cut away to cover live remarks by married Democratic presidential hopeful Sen. Gary Hart of Colorado on media reports about his alleged indiscretions with model Donna Rice. CBS's Dan Rather defended his network's decision to stick with the hearings: "The Hart story is unquestionably the more titillating, but I don't think it's more important."

The hearings took a bizarre turn with the testimony of former White House national security adviser Robert "Bud" McFarlane, who oversaw the secret program. McFarlane said that in 1985, Reagan officials and the CIA had considered a scheme for the Drug Enforcement Administration to pay $2 million in bribes and ransom to free the hostages in Lebanon. They planned to ask Texas industrialist H. Ross Perot to put up the money.

McFarlane also testified that after resigning in December 1985, he made a secret trip to Tehran in May 1986 to meet with moderate Iranian officials. The ex-Marine said he assumed he might be taken prisoner and tortured because he knew U.S. secrets, but he "had the means at hand" to prevent that. News reports suggested he carried poison pills.

McFarlane previously had confirmed reports that he gave a cake to the Iranians as a goodwill gesture.

Witnesses agreed that Marine Lt. Col. Oliver North, who had been fired from his post at the National Security Council, was the driving force behind the secret operations. The 43-year-old North began his widely anticipated testimony on July 7, dressed in his olive Marine uniform with a chest full of medals.

North was unapologetic about his actions, which he considered patriotic. He said he thought taking money from Iran to support Nicaraguan freedom fighters was "a neat idea." He admitted to previously lying to Congress about the secret campaign. "I want you to know lying does not come easy to me," he said. "But I think we all had to weigh in the balance the difference between lives and lies."

New York Times columnist Maureen Dowd wrote of North's testimony, "Through the smirks and winks and teary eyes, through the 'Peck's Bad Boy' grins and the earnest altar-boy gazes, Oliver North seemed, as always, to be starring in his own movie."

North was an instant matinee idol. "The most popular soap opera on television this week starred Lt. Col. Oliver North in the continuing saga of the Iran-Contra hearings," United Press International reported. "Ten percent more Americans watched Washington's real-life daytime drama Tuesday than normally tune in to see the soaps, game shows" and other TV shows combined, according to A.C. Nielsen, UPI wrote.

Over the next five days, the committee grilled North. He said that to conceal his activities, "he shredded documents almost daily as the operations were 'unraveling,'" The Post reported. North said his secretary, 27-year-old Fawn Hall, helped with the shredding.

After being granted immunity, Hall testified she hid documents in her blouse and boots to smuggle them out of North's office at the Old Executive Office Building next to the White House after he had been fired. Hall also became a celebrity. She was the star attraction as a guest at the 1987 White House correspondents' dinner.

The inquiry ended in early August after 41 days of hearings and 250 hours of testimony from 29 witnesses. "I believe these hearings will be remembered longest not for the facts they elicited, but for the extraordinary and extraordinarily frightening views of government they exposed," Chairman Inouye said. Lawmakers remained unclear about how much Reagan and Vice President George H.W. Bush knew about the affair.

After the hearings, special prosecutor Lawrence Walsh achieved convictions against North and 10 other government officials. North's 1989 conviction was overturned a year later on a legal technicality. In 1992, President George H.W. Bush pardoned McFarlane, former defense secretary Caspar Weinberger and four others who had been convicted.

The scandal followed McFarlane to his grave. When the former national security chief died last month at age 84, the first sentence in The Washington Post's obituary noted he was "the only official in the Reagan White House to voluntarily accept legal blame in the Iran-contra scandal."