When President Trump tweeted that Google search results are “rigged” against him and other conservatives, he tapped into a growing right-wing belief that Silicon Valley is just as much an enemy as the mainstream media, Hollywood and the Washington political establishment.

It’s not a new refrain. Conservatives have long complained of a liberal bias in the tech world, dating to the revelation of irregularities within Facebook’s “trending topics” editorial team. But the issue came to a boil over the past month after conservative conspiracy theorist Alex Jones and his InfoWars were banned from several social networks and video services.

On Tuesday, Trump turned up the heat even higher when he zeroed in on one of the nation’s largest companies and dominant valley player.

“Google search results for ‘Trump News’ shows only the viewing/reporting of Fake News Media,” Trump tweeted. “In other words, they have it RIGGED, for me & others, so that almost all stories & news is BAD. Fake CNN is prominent. Republican/Conservative & Fair Media is shut out. Illegal?”

Trump continued, alleging without offering proof that “96 percent of results on ‘Trump News’ are from National Left-Wing Media, very dangerous. Google & others are suppressing voices of Conservatives and hiding information and news that is good. They are controlling what we can & cannot see. This is a very serious situation-will be addressed!”

Google search results for “Trump News” shows only the viewing/reporting of Fake News Media. In other words, they have it RIGGED, for me & others, so that almost all stories & news is BAD. Fake CNN is prominent. Republican/Conservative & Fair Media is shut out. Illegal? 96% of.... — Donald J. Trump (@realDonaldTrump) August 28, 2018

....results on “Trump News” are from National Left-Wing Media, very dangerous. Google & others are suppressing voices of Conservatives and hiding information and news that is good. They are controlling what we can & cannot see. This is a very serious situation-will be addressed! — Donald J. Trump (@realDonaldTrump) August 28, 2018

Google disputed Trump’s assertion, saying it doesn’t “bias our results toward any political ideology.”

Trump economic adviser Larry Kudlow, asked later whether the administration thinks there should be “some form of regulation for Google,” told reporters, “We’ll let you know. We’re taking a look at it.”

Kudlow did not elaborate, and it wasn’t immediately clear what government regulation would entail. Later in the day, Trump told reporters that Google, Facebook and Twitter “better be careful” because “you can’t do that to people.”

Any effort to regulate social media companies and search engines would run up against a bevy of constitutional free speech questions. Legally, Trump doesn’t have any authority to change how Google displays search results, said Daphne Keller, director of intermediary liability at the Stanford Center for Internet and Society.

“By dictating what a private company does with search results, it legally would be like dictating what The Chronicle does with news reporting,” Keller said. “It would be a First Amendment violation.”

Google, YouTube and Twitter have won legal challenges in this area in the past because there are multiple laws — including the First Amendment — that give companies the freedom to choose what to include and exclude.

“There are a whole lot of laws that stacked up in the platforms’ favor here,” Keller said.

The online giants, however, have brought criticism on themselves through a lack of transparency about how they operate, said Renee DiResta, policy director at Data for Democracy, a nonpartisan tech research organization.

Few people understand the search, trending and recommending algorithms companies use to determine which news stories and photos pop up in Google News feeds and Facebook pages. Some users may not realize that instead of mass publishing stories like traditional news operations, these companies have customized which stories their users are seeing based on thousands of tidbits of personal information that the tech companies have harvested about them online.

“There is some legitimate criticism of how (the tech companies) have worked in the past. And those criticisms are powerful because the platforms are opaque,” DiResta said. “But those very legitimate criticisms have been co-opted by the politics.”

Corynne McSherry, legal director of the nonpartisan Electronic Frontier Foundation, testified before a House committee in April that “unfortunately, regulation of much of our online expression, thought and association has been ceded to unaccountable executives and enforced by minimally trained, overworked staff and hidden algorithms.”

Trump and other conservative critics, however, haven’t offered much of a prescription for what Congress or regulators should do.

“It’s pretty vague whether (Trump) has any concrete policy proposals here other than, ‘Tech companies are our political enemies and we should be punishing them,’ ”said Zach Graves, head of policy for Lincoln Network, a conservative organization that tries to bridge the gap between Silicon Valley and Washington, D.C. “Short of Congress doing something drastic, I don’t see much happening here.”

Over the past year, other conservatives have portrayed “the lords of Silicon Valley” — as Trump’s former top strategist, Steve Bannon, once described them — as seeing themselves as above and apart from America’s heartland.

At the California Republican Convention last year, Bannon said social media companies were part of a political establishment — along with “lobbyists, consultants, and corporatists and globalist elites” — that is ruining the country for the working class.

Last week, House Majority Leader Kevin McCarthy of Bakersfield — who has courted Silicon Valley dating to his time as a California assemblyman — tweeted about “an alarming trend of censorship against conservatives.”

“The social media phenomenon was supposed to be about radical curiosity, but it has descended into radical conformity #StopTheBias,” McCarthy tweeted.

The social media phenomenon was supposed to be about radical curiosity, but it has descended into radical conformity. This episode is the latest in an alarming trend of censorship against conservatives. ↓ #StopTheBias https://t.co/SQxfso0TFW — Kevin McCarthy (@GOPLeader) August 24, 2018

Lawrence Rosenthal, chair of the Berkeley Center for Right-Wing Studies at UC Berkeley, said Trump’s Tuesday tweets fit his pattern of talking mainly to his base.

“If you look across the entire conservative perspective, it has a little bit for everybody,” Rosenthal said. “It taps into the sense of resentment they feel toward elites ... (and) it has the quality of a conspiracy theory that allows you to easily explain and grasp things that you can’t understand. It allows you to focus on a specific group of people.”

Plus, railing on Silicon Valley carries with it the whiff of mocking “San Francisco values,” another attack line that plays well with Republicans, Rosenthal said.

“Who knows?” he said. “You could be sitting in one of those tech cafeterias across the table from Nancy Pelosi. If these companies were in Alabama, it might be a bit different.”

For its part, Google said there was nothing to Trump’s assertions.

“When users type queries into the Google Search bar, our goal is to make sure they receive the most relevant answers in a matter of seconds,” the Mountain View company said in a statement.

“Search is not used to set a political agenda and we don’t bias our results toward any political ideology,” Google said. “Every year, we issue hundreds of improvements to our algorithms to ensure they surface high-quality content in response to users’ queries. We continually work to improve Google Search and we never rank search results to manipulate political sentiment.”

San Francisco Chronicle staff writer Michael Cabanatuan contributed to this report.

Joe Garofoli is The San Francisco Chronicle’s senior political writer. Email: jgarofoli@sfchronicle.com Twitter: @joegarofoli. Sophia Kunthara is a San Francisco Chronicle staff writer. Email: Sophia.Kunthara@sfchronicle.com Twitter:@SophiaKunthara