U.S. Rep. Blake Farenthold, under fire over a sexual harassment lawsuit settled with taxpayers' dollars, ended his bid for re-election Thursday acknowledging he allowed an unprofessional and toxic atmosphere pervade his office.

"Quite simply my constituents deserve better," Farenthold said in a brief remarks carried on Facebook Live. "They deserve a primary campaign that's focused on the serious issues facing our country and our state and fixing a broken system. Therefore I'm announcing my decision not to run for re-election."

Farenthold, a four-term Republican representing Texas' Coastal Bend region, said when he first sought his seat in 2010, he "had no idea" how to run a congressional office. That allowed for what several former aides have said was a freewheeling work environment where lewd conversations took place by Farenthold and staff members.

READ FARENTHOLD'S FULL STATEMENT.

Farenthold, who plans to remain in office until his term expires in Janurary 2019, said his behavior "accommodated destructive gossip, offhand comments, off-color jokes." He promised to make amends during the rest of his tenure.

"I resolve in the coming days, weeks and months to institute meaningful changes in my official office," he said.

More:Five things to know about U.S. Rep. Blake Farenthold

U.S. House Speaker Paul Ryan, R-Wisconsin, said the Texan made the right call.

“I had a couple conversations with Blake Farenthold yesterday and I think he’s making the right decision to retire," Ryan told reporters at a news conference in Washington. He said that "unacceptable behavior has been alleged in those stories.”

Mike Bergsma, chairman of the Nueces County Republican Party, told the USA Today Network he was sorry to see Farenthold exit the race.

"It's a damn shame," he said. "He's been an excellent congressman, and I'm sorry this has happened. One wonders whether anyone could have survived scrutiny that intense."

Farenthold, who turned 56 this week, has been under intense fire since it was disclosed that he settled a sexual harassment lawsuit filed by a former aide with $84,000 in taxpayers’ money. He has said the settlement was a strategic decision to put the matter to rest even though he insists the charges are untrue.

The U.S. House Ethics Committee is looking into the allegations even though the Office of Congressional Ethics has said the allegations were unfounded.

U.S. Rep. Steve Stivers of Ohio, the leader of the of the National Republican Campaign Committee, said he agrees with Farenthold's decision to leave.

"Congress must work harder to hold ourselves to a higher standard, which is why the House took action to ensure this body is a safe and constructive workplace for all," he said. "However, there is still more work to be done.”

Editorial: My son is not a f***tard, congressman.

Farenthold's 27th District is considered safe Republican territory but Democrats pounced on the decision, saying the congressman should resign.

"What he did is unacceptable," said state Rep. Abel Herrero, D-Corpus Christi. "I think he should leave office immediately.

"He has used $84,000 of taxpayer funds to silence the accusations of sexual harassment and creating a hostile work environment," Herrero added. "Moreover, he is now embroiled in an official ongoing sexual harassment investigation."

Crystal Perkins, executive director of the Texas Democratic Party, said Farenthold "has no business holding public office."

"The fact is, Farenthold has violated the public trust and shown a pattern of demeaning, degrading, and disrespectful conduct towards women," Perkins said.

Even before Farenthold made his decision public, signs emerged that he was losing support among Texas Republicans as the campaign toward the March 6 primaries begins to shift into high gear.

More:Congressional staffers flocking to sexual harassment training

More:Farenthold 'allowed power of his office to go too far,' ex-aide says

More:Farenthold's sexual harassment settlement paid with tax dollars

Former Congressman Ron Paul, who retired after seeking the 2012 presidential nomination, said late Wednesday that he planned to back another hopeful, longtime Victoria Republican activist Michael Cloud.

“I know him to be a man of his word, principled, trustworthy and hardworking,” Paul said in a statement distributed by the Cloud campaign. “I hope my former supporters will get behind him because our country desperately needs leaders with integrity, courage and moral character. Michael Cloud is that kind of leader.”

Editorial: One way for Farenthold to live up to his promises

More:Congressional staffers flocking to sexual harassment training

Then U.S. Rep. Roger Williams announced his support for Bech Bruun, a Corpus Christi native who last week resigned as chairman of the Texas Water Development Board to challenge Farenthold. Williams was the first member of the Texas GOP delegation in Washington to publicly break with the incumbent.

“Bech is exactly the kind of person I would be proud to call a colleague in the United States Congress,” Williams, R-Weatherford, said in a news release distributed by Bruun. “Bech knows what it means to be a good steward of your hard-earned tax dollars.”

After reports surfaced that federal funds paid the harassment suit settlement, Farenthold said he would repay the Treasury. As of Thursday, he was still waiting on House lawyers to guide him through such a process and for a bank loan to clear, said Bob Haueter, his chief of staff.

The deadline for a candidate to withdraw from the March 6 Texas primaries has passed, meaning Farenthold's name will remain on the ballot, a spokesman for the Texas Secretary of State's office said.

The GOP primary field for the 27th congressional district is crowded. Bruun and Cloud are among six challengers to Farenthold. The others are Christopher K. Mapp of Port O'Connor, John Grundwald of Houston, Eddie Gassman of Corpus Christi, and Jerry Hall of Corpus Christi.

Four Democrats – Eric Holguin of Corpus Christi, Raul "Roy" Barrera of Corpus Christi, Ronnie McDonald of Bastrop, and Vanessa Edwards Foster of Houston – also are vying for the right to compete for the seat in November.

John C. Moritz covers Texas government and politics for the USA Today Network in Austin. Contact him atJohn.Moritz@caller.com and follow him on Twitter@JohnnieMo.