Congressional hearings make for historic moments, but their ultimate impact varies

The House select committee investigating the Jan. 6 Capitol riots opened with a highly orchestrated, prime-time event on Thursday that was watched by 20 million viewers, but history has shown that some of the most memorable hearings don't always produce lasting results.

While congressional hearings have led to watershed moments in U.S. history, these hearings will address new subject matter for the nation, including accusations that a defeated president orchestrated an attack on the Capitol to overturn election results.

“This is a hearing like we’ve never had before,” said Alvin Tillery, the director of the center for the study of diversity and democracy at Northwestern University. “We all saw the insurrection play out, but there’s a partisan divide over what that means. So, we just don’t know what the impact is going to be.”

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As this House committee ventures into new waters, let's take a look at five high-profile congressional hearings and their impacts:

2019 Mueller hearings

The hearing: Former special counsel Robert Mueller made his appearance on Capitol Hill more than two years after being appointed to investigate Russian interference in the 2016 election.

During his appearances in front of two House committees, Mueller kept to his vow to stay within the text of his 448 page report. While he remained tight-lipped, Mueller told lawmakers that he considered the Russian effort to interfere with the 2016 election one of the worst threats to the U.S. he witnessed.

Mueller also testified that his investigation was not a “witch hunt” and told the panel President Donald Trump was “not exculpated for the acts that he allegedly committed.”

The aftermath: Despite the long-awaited testimony, Mueller provided no shocking new information  and both parties declared the testimony a win. Democrats were quick to point out that the investigation did not exonerate Trump while Republicans said the findings dashed their colleagues’ plan to draw up articles of impeachment against the president. The House would go on to impeach Trump twice – in 2020 for abuse of power and obstruction of Congress, and in 2021 for incitement of insurrection – and the Senate acquitted him both times.

2015 Benghazi hearings

The hearings: Nearly two years after a terrorists in Benghazi, Libya, attacked an U.S. compound that left four American dead, the House formed a special select committee to investigate the incident.

The committee held several hearings, focusing on what the administration had done to improve security at U.S. embassies, before turning to invite former Secretary of State Hillary Clinton to testify about her role in the attack.

Prior to the formation of the panel, committees from the House and Senate launched probes into the attack, with Clinton testifying before both committees. During those testimonies she took responsibility for the attack, agreeing to improve security at outposts in high-threat areas.

The aftermath: The House Select Committee filed its final report in 2016 after investigating the attack for two years. The report included allegations of governmental mishandling, including CIA intelligence reports that were “rife with errors” and failure to deploy necessary military assets.

The report was overshadowed by Clinton's  exchanges with Republican lawmakers, who accused Clinton of orchestrating the intervention in Libya to boost her political career and of hiding documents.The report did not identify wrongdoing by Clinton.

Democrats reiterated concerns that the select committee was an effort to taint Clinton’s reputation, with former Maryland Rep. Elijah Cummings, the committee’s top Democrat, accusing Republicans of waiting until after the 2016 presidential election to file the final report.

1987 Iran-Contra hearings

The hearings: Officials in President Ronald Reagan's administration were accused of secretly selling weapons and missiles to Iran during its war with Iraq – despite an arms embargo – and of using proceeds from those weapons sales to fund "contra" rebels fighting the Nicaraguan government. Select committee from the House and Senate were formed and held the joint-televised Iran-Contra hearings.

During the 41 days and 250 hours of testimonies, the committees discovered bombshell revelations, including the testimony by Lt. Col. Oliver North, who admitted that he had diverted funds from deal with Iran to the contras and said he believed Reagan was aware of his actions.

The aftermath: After the hearings, the Iran-Contra committees  found that several government officials had lied to Congress and were complicit in the dealings. Eleven officials were convicted, but several of them were overturned or later pardoned, including North.

How much Reagan and Vice President George H. W. Bush knew about the dealings were still unknown to lawmakers. However, Reagan apologized to the American public in an 18-minute speech while denying he had any knowledge of the divestment of funds to the contras.

While Reagan's image took a hit with the Iran-Contra scandal, he left office with 63% of American approving of his job as president.

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1973 Watergate hearings

The hearings: The Watergate hearings took place nearly a year after five men were arrested for breaking into and illegally wiretapping the headquarters of the Democratic National Committee.

Former White House legal counsel John Dean told the committee that the Watergate complex break-in was approved by former Attorney General John Mitchell and that chief White House advisers were aware. Dean also testified that President Richard Nixon knew of the cover-up.

The hearings uncovered evidence of widespread political espionage by the Nixon administration, including illegal wiretapping by the administration as well as the existence of the Watergate tapes – recordings of White House conversations between the president and his staff.

The aftermath: As the Watergate hearings continued to play out, more evidence of wrongdoing by Nixon and his administration mounted, causing public trust of the president to wane. Nearly a year after the start of the hearings, the House Judiciary Committee adopted articles of impeachment against Nixon, including abuse of presidential powers and obstruction of justice.

Despite the knowledge of the Watergate tapes, it wasn’t until pressure from the Supreme Court that Nixon released them. Four days after he released the recordings – which included a clip of Nixon ordering one of his advisers to stop the FBI investigation into Watergate – Nixon made history as the first president to resign.

1954 Army - McCarthy Hearings

The hearings: In the midst of Republican Sen. Joseph McCarthy of Wisconsin’s aggressive investigations against suspected Communists,McCarthy found himself at the center of a series of hearings after the Army accused him of using improper influence to earn preferential treatment for one of his former staff members.

McCarthy, who stepped down from his role as chair of Senate Permanent Subcommittee on Investigations for the hearing, in turn accused the Army of trying to derail his investigation into security practices. Boston lawyer Joseph Welch was hired by the Army to make their case against the Wisconsin senator.

During one of the hearings’ sessions, McCarthy – who was known for his reckless accusations – brought charges that a member of Welch's team had ties to a Communist organization.

“You've done enough,” Welch told McCarthy as he continued his attack. “Have you no sense of decency, sir, at long last? Have you left no sense of decency?”

The aftermath: The televised hearings, including the interaction between Welch and McCarthy, placed McCarthy in a “increasingly unattractive light” as he badgered witnesses, ignored parliamentary procedures and lacked common courtesy, according to the Senate Historical Office.

His behavior during the hearings not only damaged his reputation with the public, but with his colleagues as well. McCarthy was later censured by the Senate and ostracized by his party.

More coverage of Jan. 6 hearings for USA TODAY subscribers

• Miss the Jan. 6 hearing?: Here's what Bill Barr, Ivanka Trump, Capitol Police and others said

• By the numbers: Who has been arrested in the Jan. 6 Capitol riot

• Tears, tissues, T-shirts: What it was like in the room during the Jan. 6 committee hearing

• Betsy DeVos: Trump’s actions on Jan. 6 were ‘line in the sand’ that led to resignation

• 'Very strange and somewhat alarming': White House, Justice aides offer insider accounts of Jan. 6 Capitol attack

This article originally appeared on USA TODAY: How Jan. 6 congressional hearings compare with other historic moments