These would be 1st Amendment violations of the highest level.
Let's be sure to properly understand the First Amendment itself before calling something a First Amendment violation.
I'm not a lawyer or constitutional scholar and I know of none who participate here on EO. So, being careful to properly understand the First Amendment, I did a little Googling and learned the First Amendment itself is part of the US Constitution. More specifically, it is an amendment to the Constitution (actually the first of several amendments, thus the name First Amendment). It was was adopted in 1791.
The First Amendment says this:
Congress shall make no law respecting an establishment of religion, or prohibiting the free exercise thereof; or abridging the freedom of speech, or of the press; or the right of the people peaceably to assemble, and to petition the Government for a redress of grievances.
There are numerous explanations online telling readers what the First Amendment means. Two are shared below.
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The First Amendment (Amendment I) to the United States Constitution prevents the government from making laws that regulate an establishment of religion, or that prohibit the free exercise of religion, or abridge the freedom of speech, the freedom of the press, the freedom of assembly, or the right to petition the government for redress of grievances. It was adopted on December 15, 1791, as one of the ten amendments that constitute the Bill of Rights." (
Wikipedia)
"The First Amendment guarantees freedoms concerning religion, expression, assembly, and the right to petition. It forbids Congress from both promoting one religion over others and also restricting an individual’s religious practices. It guarantees freedom of expression by prohibiting Congress from restricting the press or the rights of individuals to speak freely. It also guarantees the right of citizens to assemble peaceably and to petition their government." (
Legal Information Institute)
Twitter, Truth Social, Facebook, Reddit, Instagram and other social media entities are not the government, the press, a church. Social media entities, as they exist today, are businesses run for profit. Some are publicly held, meaning their shares trade on stock exchanges, but they are not public entities like city hall is a public entity owned by the people of that city. As long as they obey the law, social media companies are free to operate any way they choose for any purpose they choose.
While a host of laws apply to businesses of all kinds, I know of no constitutional provision or any law that prevents a social media entity from kicking Trump or any other person off its site.
When an entity gets big like Twitter or Facebook, all sorts of people proclaim what they think that entity's rules should be. But it remains a fundamental fact that social media sites are free to make their site-participation rules, and they are free to grant or deny participation, and to regulate the nature of that participation as they please ... as long as they follow the laws that apply to those businesses.