The letter was widely shared on social media, with comedian Stewart, who joined Twitter following Trump’s departure from office, mocking him.
Many critics noted that Trump, who first joined the union in 1989, signed the letter “President Donald J Trump”, despite Joe Biden taking office on 20 January.
On Thursday (4 February), the former president responded to news that SAG-AFTRA’s board had “overwhelmingly” voted that Trump violated their guidelines by inciting the Capitol insurrection.