How far will the anti-Trump forces go in crushing their opposition?

That tweet is a response to the news: "Simon & Schuster Cancels Plans for Senator Hawley’s Book/The publisher faced calls to drop the Missouri Republican’s upcoming book, 'The Tyranny of Big Tech,' following criticism of his efforts to overturn the presidential election" (NYT). 
“We did not come to this decision lightly,” Simon & Schuster said in a statement. “As a publisher it will always be our mission to amplify a variety of voices and viewpoints: At the same time we take seriously our larger public responsibility as citizens, and cannot support Senator Hawley after his role in what became a dangerous threat.”... 

“This could not be more Orwellian,” he said. “Simon & Schuster is canceling my contract because I was representing my constituents, leading a debate on the Senate floor on voter integrity, which they have now decided to redefine as sedition... We’ll see you in court."... 
The subject of Mr. Hawley’s book... is not about the election or Mr. Trump, but about technology corporations like Google, Facebook and Amazon. Its cancellation was remarkably swift and raised questions about how publishers will approach future books by conservatives who have supported Mr. Trump’s efforts to invalidate the election....

ADDED: Here's Hawley's full statement:

I'm not sure what his "First Amendment" theory is, but I'd love to see his explanation. There's a folk meaning of "First Amendment" that simply means "freedom of speech," but Hawley is a Yale Law School graduate who had a clerkship with Chief Justice John Roberts, so we must attribute the highest level of constitutional law understanding to him. I await the explication!

ALSO: Hawley's book about the "tyranny" of Google, Facebook, and Amazon ought to discuss the problem of the repression of freedom of speech, and for all I know, he's got some sophisticated First Amendment theory in there. Send me a PDF of your book, Josh — or just the pages with the First Amendment material. I will give it a sympathetic read!