Increasingly isolated and prone to conspiracy theories, President Trump in recent weeks has become fixated on the idea that the country’s largest tech giants — Google, Facebook, and Twitter — are silencing his conservative base.

Trump has come to view his supposed mistreatment at the hands of Silicon Valley as emblematic of a wide-reaching campaign to undermine his presidency, according to a half dozen current and former administration officials and others close to the White House.

Even though he doesn’t use a computer and is seen by those around him as tech neophyte, the president knows a powerful wedge issue when he sees one. As he has throughout his political career, Trump is amplifying for maximum potency a more nuanced idea already coursing through the conservative ecosystem – just as he’s cast the press as an “enemy of the people” and dismissed NFL players who kneel during the national anthem in protest of police brutality.

“What President Trump is an expert at is gauging what his supporters care about,” said Andy Surabian, a Republican strategist and former White House aide. “This issue has really risen up – on par with issues like immigration, judges and the Second Amendment – in terms of issues that Trump supporters care about.”

In public comments and private conversations with his allies, Trump has often brought up the issue, bashing the San Francisco tech elites who he believes worked in 2016 to get his political nemesis, Hillary Clinton, elected president. It’s also become an official White House position, after the communications office distributed talking points last week to outside surrogates titled “Big Tech is Suppressing Conservative Voices.”

The talking points, which were obtained by POLITICO, highlight a New York Times story about Facebook employees alleging on an internal message board that the company is “intolerant” of perspectives that differ with its left-leaning culture. The talking points also target Twitter for discriminating against Republicans by limiting users’ ability to find them in searches, and Google for showing the word “Nazism” next to search results for the California Republican Party.

A White House spokesman did not respond to a request for comment for this story.

The tech companies have repeatedly rejected the idea that their platforms are intentionally biased. They argue that in cases where partisan leanings are detected in their algorithms, design choices, or enforcement decisions, they are quickly fixed. The supposed record of bias, their defenders argue, is hugely anecdotal.

But conservatives have in recent years repeatedly pointed to signs that the tech industry’s liberal leanings are manifested in the tools they have built, typified by so-called “shadow banning” or the quiet suppression of Republican activity on the social-media platforms.

The president’s embrace of anti-Silicon Valley rhetoric has been shaped by advisers who see it as the latest front in the country’s long-running culture wars and believe it has the potential to rally conservative voters ahead of the midterms and the president’s own reelection in 2020. They include Brad Parscale, the campaign manager of Trump’s reelection campaign, Donald Trump, Jr., the president’s son, Republican National Committee Chairwoman Ronna Romney McDaniel and Fox News personalities Sean Hannity, Laura Ingraham and Tucker Carlson.

In May, Parscale and McDaniel wrote a letter to Facebook CEO Mark Zuckerberg and Twitter CEO Jack Dorsey demanding an end to “bias against conservative content.” Parscale and McDaniel met with Facebook executives in June alongside House Majority Leader Kevin McCarthy, who conservatives see as another major conduit between the tech companies and the president.

The California Republican helped popularize the hashtag #StopTheBias, which has been picked up by Trump and top surrogates like Donald Trump Jr. McCarthy has had several conversations with the president about social media bias, using personal anecdotes and examples of the companies' slanted treatment against conservatives to drive home his point, according to a Republican with knowledge of their discussions.

“Conservatives invested a lot of money in building up their Facebook presences, and they did really well for a while,” Zach Graves, head of policy at the San Francisco-based right-of-center tech advocacy group Lincoln Network, told POLITICO. “Then Facebook changed the algorithm, and engagement dropped off a cliff. Now they’re practically worthless.”

Conservative allies of the White House have publicly suggested a range of policy remedies, including imposing government oversight of the tech sector by treating companies like public utilities. Another option being discussed informally in conservative circles: a push to eliminate tech companies’ protections under Section 230 of the Communications Decency Act, which limits firms like Google’s liability for the content hosted on their platforms.

Rumors have circulated in Washington in recent days that the White House is workshopping ideas for a Google-targeting executive order. Several people inside the White House denied working on such a project.

The roots of conservative suspicions about social media can be traced back to a May 2016 report by the tech publication Gizmodo in which an unnamed Facebook source said the site’s in-house curators “routinely suppressed conservative news” in its trending news section. Coming at the height of the fraught U.S. presidential primaries — Trump was in the final weeks of sewing up the Republican nomination — the debate quickly became highly politically charged.

The president, who tweets avidly but doesn’t use a computer or consume social media himself, has repeatedly tweeted about his frustrations with tech companies, accusing Google of rigging search results to only show stories from the “Fake News Media” and Twitter “shadow banning“ prominent Republicans.

“[V]irtually all of those companies are super liberal companies in favor of Hillary Clinton,” Trump said in a Tuesday interview with the Daily Caller, accusing tech firms of interfering in the 2016 and 2018 elections.

The Justice Department signaled this week that it is taking the president’s concerns seriously. In a Wednesday statement, the department announced that Attorney General Jeff Sessions is organizing a meeting, slated for Sept. 25, with state attorneys general “to discuss a growing concern that these companies may be hurting competition and intentionally stifling the free exchange of ideas on their platforms.”

In response to a Trump tweet criticizing Google last week, Larry Kudlow, the president’s top economic adviser, even said the administration is “taking a look” at imposing regulations on the internet giant, sending shockwaves through the tech world as it scrambled to figure out what such a move might look like.