Updated at 4:15 p.m. with comment from Texas Sen. John Cornyn.

WASHINGTON — Rep. Joe Barton, whose private life came under national scrutiny after sexual images he shared in an extramarital relationship were made public, won’t seek re-election.

The Ennis Republican announced his retirement in an interview Thursday with The Dallas Morning News, three weeks after saying he would seek an 18th term.

"I’ve always listened to people in Texas and worked for them in Washington, and I’ve been listening to a lot of people the last week in Texas," he said. "...There are enough people who lost faith in me that it’s time to step aside and let there be a new voice for the 6th district in Washington, so I am not going to run for re-election."

The about-face ends a congressional career that spans more than three decades and — until last week — was most noted for his contentious relationship with environmentalists as former chairman of the powerful House Energy and Commerce Committee.

He’s faced crushing pressure in recent days after lewd images and suggestive messages he swapped during extramarital relationships surfaced online, an event that prompted a number of women with whom he was involved to speak publicly about their exchanges with Barton.

But unlike other high-profile men who’ve seen their careers crumble recently in politics, Hollywood and the news media, none of Barton’s accusers have said he engaged in sexual harassment or abuse of power.

Barton publicly apologized for what he described as consensual sexual relationships with multiple women while married to his former wife. That marriage — Barton’s second — ended in 2015.

On Thursday, Barton reiterated that the relationships were consensual. "I am not guilty of sexual harassment," he said.

Barton said he believes he still has the support of much of his district, and could win, if he ran. “But it would be a nasty campaign, a difficult campaign for my family,” he said.

Barton said he made up his mind on Wednesday, but not just because a growing number of Republicans have called for him to step aside.

His 12-year-old son Jack asked him not to run, he told The News. When he asked why, Jack told him: "Well, you've done a lot of good. You have a good record, and you don't need to keep running to prove that," he said.

First elected to Congress in 1984, Barton is the longest-serving member of the Texas delegation.

National reckoning

A month ago, Barton wasn’t ready to call it quits, despite the exodus of lawmakers in a raucous political climate under President Donald Trump. A half-dozen Texans in the U.S. House have already announced their departure at the end of this term, including two committee chairmen.

But Barton is facing pressure to leave amid a national reckoning over sexual misconduct and harassment, momentum that has led to the ouster of such high-profile men as Hollywood mogul Harvey Weinstein, veteran journalist Charlie Rose and, more recently, Today show staple Matt Lauer.

Congress has also been rocked with allegations of misconduct, leading both the House and Senate to mandate sexual harassment training.

In recent weeks, lawmakers including Minnesota Sen. Al Franken and Michigan Rep. John Conyers, both Democrats, have been accused of groping and other inappropriate behavior.

In Alabama, Senate hopeful Roy Moore, a Republican, has denied allegations he pursued sexual relationships with teens while in his 30s and rejected calls to exit the race.

Barton, 68, hasn’t been accused of abusive behavior. Nor is he known as a religious crusader, though he’s supported legislation that would ban same-sex marriage.

Barton owned up last week to being the man in a salacious image bouncing around social media. The photo showed him nude, with genitals obscured, apparently a screen shot from a video of him masturbating. That video would later be posted on a conspiracy theory website.

Barton, who is engaged to be married a third time, said he long ago told his fiancee about past transgressions. "These activities, as unsavory as they may be, were from the past, not the present, and I'm never going to do them again," he said.

Considered the dean of the Texas delegation, Barton broke the retirement news to his GOP colleagues at a weekly luncheon on Thursday.

Texas Sen. John Cornyn later told reporters he respects Barton's decision, and said: "He's been a friend and somebody who has always kept what is in the best interests of Texas at the forefront."

Mounting pressure

Still, his decision to share lewd messages, even if in a consensual context, drew rebukes from Republicans in his own district — with many of them already offering up potential replacements while warning that, if he remained on the ballot, he would hurt other GOP candidates.

Pressure grew Wednesday when state Sen. Konni Burton of Tarrant County, a tea party conservative, joined other local leaders in saying he should drop his 2018 plans. Meanwhile, an Arlington Republican woman came forward with suggestive messages Barton sent at some point during a two year correspondence, something the congressman acknowledged.

Barton rejected suggestions his candidacy could affect others down ballot, but said he respects and understands their disappointment.

"I’m at peace with it," he said of his decision. "I’m not happy about what’s gone on. But I did do the things and I’ve always been truthful ... You have to be accountable for your actions, and I'm trying to do that."

Others have said that, no matter his decision, Barton is a victim of a cruel misdeed.

It's still uncertain how the person who initially released the images on Twitter obtained them. She has declined interview requests from The News.

On Thursday, Barton said he does believe he's a victim of "revenge porn" and that an investigation is underway. He declined to give specifics, but said he does not believe he knows the person who released the images through an obscure Twitter account.

“I have no clue as to the motive of who did this," he said.

Texas law prohibits the malicious release of sexually explicit images or material without the depicted person’s permission.

This week, a bipartisan group of lawmakers in Congress announced plans for legislation that would make it a federal offense. Barton said he'd vote in favor of the bill.

Legislative career

Long before the sexting revelation threatened to overshadow Barton’s decades-long congressional career, the former natural gas consultant was best known as a powerful ally of Texas’ oil and gas industry.

It was as chairman of the House Energy and Commerce Committee, a role he held from 2004 to 2007, that Barton first rose to national prominence.

He sponsored the Energy Policy Act of 2005, which was subsequently signed into law by former President George W. Bush. The policy banned the federal government from requiring companies to disclose chemicals they used, unless states required it — a decision cheered by the energy industry but abhorred by environmentalists.

He's also frustrated Democrats and environmental advocates with his denial of human-caused climate change.

Ten years ago, during a committee hearing on climate change, he famously told former Vice President Al Gore "you're not just a little off, you're totally wrong" on the role of carbon dioxide emissions in global warming.

He made headlines again in 2010 for apologizing to the head of oil giant BP for what he called a “$20 billion shakedown” by the Obama White House over its requirement that the company establish a relief fund for those affected by the Gulf Coast oil spill.

He later apologized for using the term “shakedown” and retracted his apology to BP.

Barton earned the nickname "Smokey Joe" in a 2003 Dallas Morning News editorial for his attempts to protect Ellis County and its Midlothian cement plants from environmental regulators.

"Congressman Barton has a reputation of being one of the more anti-environmental members of Congress," said Craig Auster, partnerships director for the League of Conservation Voters, which gives Barton a zero percent rating for his environmental voting record in 2016. "Anytime we see someone who is so pro-polluter decide to leave Congress is a good day."

Barton, now the vice chairman of the energy committee, is overseeing the re-authorization of the Department of Energy and helping lead a task force dedicated to getting federal aid for Harvey recovery -- though he’s voted against a number of relief bills over concerns it would raise the national debt.

He also led a successful effort to lift a 40-year ban on crude oil exports in 2015, a move that has led to a rise in demand for U.S. product.

Though he's a member of the conservative House Freedom Caucus, Barton has drawn some criticism from within his own party for his stance on immigration.

He's the sole Lone Star Republican to sign on to the latest DREAM Act, a bipartisan bill that would protect from deportation children brought to the country illegally. He's called for a path to citizenship for the so-called Dreamers, whose fates are uncertain as President Donald Trump phases out the Deferred Action for Childhood Arrivals program.

Earlier this week, a new Republican candidate for his district — retired U.S. Navy pilot Jake Ellzey — cited Barton’s support for Dreamers as a reason some voters are unhappy with him back home.

But on Thursday, Barton warned that Republicans must expand efforts to reach out to Hispanic voters.

"The Texas Democrats are coming back and we, as Republicans, if we don't deal with the immigration issues, the DACA issue and reach out to Hispanics, the Democratic party in Texas is going to make a surge very quickly," he said.

Texas Democrats cheered his retirement news. A handful had announced plans to run for Barton’s seat even before the sexting issue.

“Texans are right to believe that public servants (on both sides of the aisle) should be held to the highest moral and ethical standard,” Texas Democrats executive director Crystal Perkins said.

Barton said he's inclined to vote for Tarrant County Tax Assessor-Collector Ron Wright, his former chief of staff and district director, who announced plans to run late Thursday.

Asked if he'd endorse him, Barton joked: "Given my current status, I'm not sure if anybody would want my endorsement, so I might come out against somebody if that helps them.”

Baseball shooting

Barton was on the field last June when a lone gunman opened fire on the GOP congressional baseball team, gravely wounding House Majority Whip Steve Scalise. Barton, the team’s longtime manager, sought cover with two of his sons: Brad, from his first marriage, and youngest son, Jack, from his second.

.@RepJoeBarton and his sons board the subway in the Capitol after a shooting at the Republican's baseball practice in Va. #baseballshooting pic.twitter.com/4lrc80frcj — Tom Williams (@pennstatetom) June 14, 2017

Afterward, he broke down in front of reporters when discussing the ordeal, praising the U.S. Capitol Police officers who stopped the shooter.

'It was scary': Rep. Joe Barton describes shooter, says Capitol police are "heroes." https://t.co/gU44ZCKcv8 — MSNBC (@MSNBC) June 14, 2017

Barton would go on to introduce the "Wounded Officers Recovery Act" with Pennsylvania Rep. Mike Doyle, who manages the Democratic baseball team.

The bill allows donations to a fund for Capitol Police injured in the line of duty. It was signed into law in August.

Future plans

Unlike other Texas lawmakers who have carefully plotted their retirement news, Barton said he isn't sure what will happen when he leaves office.

"I'm going to have to do something. I'm not a wealthy man," he said, noting that his youngest son has a college education ahead. "I have no idea what I'll be doing a year and a half from now."

The sexting revelation has held a place in Barton's Wikipedia page for days. Asked how he'd prefer for people to think of him, he quipped: "I don't know that too many people are going to want to think about Joe Barton very much longer."

He then paused to collect himself. "I want my family to know that I love them," he said. "And I want the people of the 6th District to know that I have, in my official capacity, never violated my oath of office. My private life hasn’t been exemplary, but my public life has been ... I’ve always voted what I thought was the right vote.”

Washington correspondents Tom Benning and Nicole Cobler contributed to this report.