A shocking new poll from Pew Research shows that a vast majority of conservatives who regularly post on social networks believe technology companies and websites like Facebook, Twitter, and Google regularly censor political posts and silence conservative views.

Adweek reports that the poll, which surveyed 4,594 U.S. adults, found that around 72% believe that social networks have some control over political posts, and that Facebook and Twitter regularly censor some political information that opposes their corporate viewpoint.

But conservatives were far more likely than Democrats to believe that they were the ultimate targets of censorship; 85% of conservatives reported feeling marginalized by social networks, while 64% believe the most popular social networks have a decidedly liberal bent. Among Democrats, 43% “saw no bias” and 53% believe “that tech companies support both sides equally.”

The news comes just as Twitter begins an overture aimed at convincing conservatives that the network exhibits no political bias in enforcing its rules, even though big name conservatives, like @GayPatriot, say they’ve experienced Twitter’s bias firsthand (@GayPatriot, for example, was suspended for “harassing” Chelsea Manning, after pointing out that Manning had been convicted of espionage against the United States).

According to The Washington Post, Twitter’s Jack Dorsey “convened a rare private dinner with Republican leaders and conservative commentators in Washington” last week to “build ‘trust’ among conservatives who have long chastised the company,” vehemently defending his network against charges that conservatives were unfairly targeted under the network’s “anti-harassment” policies.

Twitter — and Facebook — have a long way to go before conservatives believe their contentions, though, according to Pew. Only “3 percent believe those companies can be trusted to do the right thing ‘just about always’ and 25 percent ‘most of the time.'”