• by Wendy Davis  @wendyndavis, May 13, 2020

Sen. John Cornyn (R, Texas) is violating people's First Amendment rights by blocking them on Twitter, an advocacy group says.

“Multiple federal courts have held that a public official who uses a social media account for official purposes, and allows the general public to comment or post replies to that account, has created a public forum and may not block individuals from that forum based on viewpoint,” the Knight First Amendment Institute at Columbia University writes in a letter sent to the lawmaker Wednesday.

The organization is urging Cornyn to "immediately" stop blocking people based on their viewpoints. 

The Knight Institute tells Cornyn it's representing Heath Mayo, a former intern for Cornyn and a constituent, who says he was blocked by the lawmaker after criticizing him on Twitter.

Cornyn blocked Mayo after he replied to a March tweet by Cornyn that stated: “Be smart; don't panic. We will get through this #coronavirus,” and showed a picture of a Corona beer bottle on a table in what looked like a restaurant or bar.

“I just don’t understand the thought process that gets a senior-ranking Senator to say, 'You know what? I think I'll post this picture of a Corona beer in an empty restaurant where I'm dining, in direct disregard of CDC & gov't guidance -- a gov't for which I'm a spokesman,'” Mayo tweeted in response.

Several weeks later, Mayo tweeted that he had been blocked. “Woah. Just realized my own Senator for whom I once interned has now blocked me, presumably for this tweet,” Mayo posted. “Sorry, John -- the R next to your name doesn’t put you above criticism.”

Cornyn was also sued late last month by Tod Beardsley, director of research at Massachusetts-based cybersecurity firm Rapid7, who alleged he was blocked by the lawmaker. After the lawsuit was filed, Beardsley was unblocked. Cornyn's spokesman also told the Austin American Statesman the block was inadvertent.

Earlier this year, a federal appellate court ruled that President Donald Trump violated the First Amendment by blocking critics on social media.

The Department of Justice hasn't yet said whether it plans to ask the Supreme Court to review that ruling.