Tweets on Wednesday by Donald Trump Jr. capped more than a month of efforts by President Trump’s allies to surface the supposed name of a whistleblower whose complaint about a July 25 phone call led to the House’s impeachment inquiry.

Most news organizations, including The Washington Post, have withheld the name of the whistleblower, whose complaint about Trump’s call with Ukrainian President Volodymyr Zelensky has been largely confirmed by diplomats and others with firsthand knowledge as well as by a reconstructed transcript released by the White House. The whistleblower’s name has been kept confidential by U.S. officials, in line with federal law designed to prevent retaliation.

But the supposed name of the whistleblower has been circulating in conservative corners of social media since at least Oct. 3, culminating in Trump Jr.’s Wednesday morning retweet of a Breitbart News article that named an individual. During one 24-hour period last week, the CIA officer’s name was mentioned in more than 150,000 tweets.

The same officer has also been the subject of an advertising campaign on Facebook, financed by, among others, a North Carolina businessman whose Facebook page is aimed at Christian users. The ads, in which the supposed name of the whistleblower appeared, were viewed several hundred thousand times before Facebook removed them Wednesday in response to a query from The Post.

The campaign on social media to out the whistleblower, who has legal protection from retaliation, intensified as Trump and his allies in Congress ramped up their calls for the individual to be identified. Sen. Rand Paul (R-Ky.) demanded at a Trump rally on Monday that mainstream news organizations provide a name. These calls were quoted in tweets from Russian state media organizations RT and Sputnik.

Sen. Rand Paul (R-Ky.) urged the media to print the name of the whistleblower during a Nov. 4 campaign event for Kentucky Gov. Matt Bevin (R). (The Washington Post)

The Web-enabled effort to identify the whistleblower illustrates the ability of Trump and his allies to use an army of conservative commentators and social media provocateurs to spread the president’s version of events and combat his critics. Trump displayed his willingness to organize these foot soldiers at his “social media summit” over the summer, to which many of the same commentators were invited.

Trump has called for the whistleblower to be outed, saying he has a right to “meet my accuser.” But if Trump believes the outlets that he promotes, he already knows his accuser’s name.

The paid Facebook posts in particular alarmed whistleblower advocates. An attorney for the whistleblower, who declined to name his client, said Facebook and others have an ethical responsibility to protect “those who lawfully expose suspected government wrongdoing.”

“This is particularly significant in this case where I have made it clear time and time again that reporting any suspected name for the whistleblower will place that individual and their family at risk of serious harm,” said the attorney, Andrew P. Bakaj. “To that end, I am deeply troubled with Facebook seeking to profit from advertising that would place someone in harm’s way. This, frankly, is at the pinnacle of irresponsibility and is intentionally reckless.”

Bakaj, in a letter to the White House dated Thursday, demanded that Trump stop calling for the publication of the whistleblower’s identity and alleged that his “reckless and dangerous” comments already had intimidated the whistleblower. “Let me be clear: should any harm befall any suspected named whistleblower or their family, the blame will rest squarely with your client,” said the letter, addressed to Pat Cipollone, counsel to the president, and copied to congressional leaders. The letter was first published by CNN and confirmed by The Post.

The person named in Trump Jr.'s tweets — as well as in the articles he amplified — did not respond to a request for comment. A spokesman for the president’s elder son, Andrew Surabian, when asked by The Post about Trump Jr.'s posts, cited his several tweets on the subject, including one noting previous online conversation about the whistleblower’s supposed name and expressing surprise about the controversy on Wednesday. “Are they going to pretend that his name hasn’t been in the public domain for weeks now?” Trump Jr. tweeted.

Far-right Internet personalities with ties to the president have labored to give credence to claims about the whistleblower’s identity, which has been the subject of speculation on the Web since the first days after details of the complaint became public.

Jack Posobiec ― a Trump supporter who pushed the debunked Pizzagate conspiracy theory that prominent Democratic politicians were involved in a child sex abuse ring and is now a correspondent for the conservative One America News Network — tweeted the name of the CIA officer on Oct. 3, two weeks after elements of the whistleblower’s complaint became public.

Posobiec said his initial mention of the CIA officer’s name, suggesting it “sounds like” that person was the whistleblower, was an educated guess based on what he had read in a New York Times article and on background Posobiec already knew about several people suspected of being the whistleblower. The Times article, published on Sept. 26, carried the headline, “Whistle-Blower Is a C.I.A. Officer Who Was Detailed to the White House.”

“You could pretty much read between the lines,” Posobiec said.

His initial reference drew some immediate attention. But Posobiec’s reach paled next to the torrent that came when other accounts, including that of conservative commentator Dinesh D’Souza, mentioned the same name on Twitter. One account, @GregRubini, tweeted the same CIA officer’s name more than 20 times.

The push on Twitter intensified last week, when an article appeared on RealClearInvestigations, which is backed by foundations associated with conservative causes, including the Ed Uihlein Family Foundation and the Sarah Scaife Foundation. The article, by the conservative author Paul Sperry, whose books include “Infiltration: How Muslim Spies and Subversives Have Penetrated Washington,” made a detailed argument that the individual was the whistleblower.

The article elaborated on claims about the whistleblower’s identity that Sperry made in a tweet that had prompted Posobiec’s initial offer of a name Oct. 3. Sperry’s tweet included claims about the individual’s partisan affiliation and the timing of his assignments that weren’t in the Times article.

The steep climb in Twitter references to the named person peaked the day after the RealClearInvestigations article’s publication, according to research by Darren Linvill, an associate professor of communication at Clemson University.

The president retweeted talk radio host Mark Levin over the weekend, sharing a Breitbart article that included the purported name of the whistleblower. That move delighted Trump’s supporters, but it was his elder son’s decision to more clearly include the name in his own tweet — and to double down on the decision in subsequent posts — that gave the online crusade a sense of victory.

“KA BOOM! Donald Trump Jr. Tweets Name Of Whistleblower,” the right-wing website Gateway Pundit celebrated.

Mike Rothschild, a researcher whose book debunking major conspiracy theories is scheduled to be published in January, said the RealClearInvestigations story was a turning point because it provided a false air of authority.

The pursuit of the whistleblower’s identity illuminated how a “community that believes Donald Trump can do no wrong” has melded with a “big conspiracy theory community,” Rothschild said. Vindication of their claims could end up solidifying their fan base, he said, noting that prominent purveyors of the QAnon conspiracy theory jumped on the bandwagon, along with doggedly pro-Trump pundits. Together, these communities project enormous influence online, in part through followings that experts think are sprinkled with inauthentic accounts controlled by automated software.

“When these cranks start spreading this around, it gains credence because so many people share it,” Rothschild said. “It’s impossible to get out.”

Tom Kuntz, the editor of RealClearInvestigations, defended the decision to publish the name, saying, “We aggregate investigative news across the political spectrum, and when we see gaps, we look at them and decide whether to go after them.”

He declined to say whether Sperry had seized on the name because of his back-and-forth with Posobiec on Oct. 3, saying Sperry had credible sources and also relied on reporting from other outlets, including the Times, which “wrote a long piece going into detail about him about a month ago, saying he was a CIA analyst, blah blah blah,” Kuntz said. The Times didn’t respond to a request for comment about its Sept. 26 article.

Kris Coratti, a spokeswoman for The Post, said: “The Washington Post has long respected the right of whistleblowers to report wrongdoing in confidence, which protects them against retaliation. We also withhold identities or other facts when we believe that publication would put an individual at risk. Both of those considerations apply in this case.”

The intelligence officer named as the supposed whistleblower previously had been a target for far-right provocateurs, who accused him in summer 2017 of leaking anti-Trump news. Rep. Louie Gohmert, a Texas Republican and Trump loyalist, mentioned his name last month during a congressional hearing focusing on Puerto Rico. He was pressing Natalie Jaresko, Ukraine’s former finance minister and now executive director of the Financial Oversight and Management Board for Puerto Rico, to discuss conspiracy theories about Ukraine’s involvement in the 2016 presidential election.

President Trump Nov. 3 called the inquiry into his phone call with Ukraine's president "an impeachment scam ... between the Democrats and the fake news media." (The Washington Post)

As Trump and his allies intensified their calls for the whistleblower to be identified, some groups on Facebook assumed responsibility for fulfilling the president’s demands, publishing the name not only on their own pages but enlisting Facebook’s paid promotion tools to get the individual’s name in front of hundreds of thousands of users who may not have sought out such content on their own.

Facebook’s initial acceptance of the ads, some of which had been published last month, could inflame criticism of the platform, which has come under scrutiny for spreading disinformation, threats and hate speech, as well as permitting politicians to lie in their ads.

“If the ads are meant to intimidate and harass and threaten people, that would be wrong, and it might be illegal,” said John N. Tye, a former State Department official who became a whistleblower in 2014 and later founded the nonprofit Whistleblower Aid, which has been supporting the legal team working with the individuals in the Ukraine case. “Certainly if it were being commercialized, getting paid to participate in that would be wrong,” Tye said.

A Facebook spokesman said all of the ads identified by The Post were being removed.

“Any mention of the potential whistleblower’s name violates our coordinating harm policy, which prohibits content ‘outing of witness, informant or activist,'" the spokesman, Andy Stone, said.

A North Carolina businessman and failed congressional candidate, Tim D’Annunzio, gained as many as 200,000 impressions on a pair of ads that provided the supposed name of the whistleblower. He promoted the posts using a personal page titled “Message,” targeting “people who are Christian-related, who have Christian interests,” he said in an interview.

D’Annunzio said he first came across the name of the supposed whistleblower in a Gateway Pundit article. “And then it started to pop up in other places, where it’s obvious he’s the guy,” he said.

One of D’Annunzio’s ads, viewed as many as 150,000 times, provided the supposed whistleblower’s full name and links to the RealClearInvestigations article. “Impeachment is another setup,” the ad claimed. The other post, viewed as many as 50,000 times, similarly provided the name.

The Washington Post’s Karoun Demirjian dissects the Republicans latest push to unmask and subpoena the whistleblower. (The Washington Post)

D’Annunzio, who said he owns several skydiving businesses, gained those views for about $1,000, according to Facebook’s ad archive.

Another paid post, by a group called Americans Are Pissed, promised to identify “who all the players are behind this coup!” The associated website hosts conspiratorial, right-wing content. A request for comment went unanswered.

Another ad, placed by a group called Arab American Conservative, gained as many as 6,000 views, mostly from users older than 50 in a handful of politically potent states, including Pennsylvania, Ohio, Michigan and Florida. The individual thought to manage the page didn’t respond to a request for comment. An attorney in Texas also promoted a post revealing the name of the supposed whistleblower and calling him an “illegal SPY.”

Shane Harris and Greg Jaffe contributed to this report.