Yeah, they do.
The First Amendment to the U.S. Constitution opens with sweeping language: “Congress shall make no law… abridging the freedom of speech.” It makes no obvious distinction between citizen and non-citizen, seemingly protecting all “people” within America’s borders. ContentsThe Constitutional...
govfacts.org
"The First Amendment to the U.S. Constitution opens with sweeping language: “Congress shall make no law… abridging the freedom of speech.” It makes no obvious distinction between citizen and non-citizen, seemingly protecting all “people” within America’s borders."
"The First Amendment protects the rights of
“the people” to assemble and petition the government. Its speech protections aren’t limited by citizenship status. For over a century, the Supreme Court has confirmed that non-citizens within the U.S. are
“persons” protected by the Due Process Clauses of the Fifth and Fourteenth Amendments."
"This interpretation means many basic constitutional rights, including freedom of speech and religion,
apply to citizens and non-citizens alike. However, the judiciary has carved out significant exceptions."
"Non-citizens seeking to enter the United States have the fewest First Amendment protections. The Supreme Court has consistently held that
there’s no constitutional right to enter the country, giving the government its broadest authority in this domain."
"Once lawfully admitted into the United States, a non-citizen’s constitutional status changes significantly. They become
“invested with the rights guaranteed by the Constitution to all people within our borders”. However, a critical gap emerges between protection from criminal prosecution for speech and vulnerability to severe immigration consequences for the same speech."
"Lawful Permanent Residents (LPRs or “Green Card” holders) enjoy broad First Amendment protections. They can
criticize the government, participate in protests, and advocate for political causes without facing criminal charges based solely on their speech."
"However, these protections don’t shield them from immigration-related actions. Federal law allows the government to deny an LPR’s citizenship application or initiate deportation proceedings if their speech or associations are deemed a national security threat."
"
Individuals on temporary visas, such as students and workers, are also protected by the First Amendment and have
rights to free speech and peaceful assembly. They can participate in protests and express political views.
However, their status is conditional and more fragile than LPRs. An arrest during a protest, even if charges are dropped, or university disciplinary action related to activism, can be used by immigration officials as
basis to revoke their visa or deny future applications. This vulnerability creates a powerful
“chilling effect,” where visa holders may self-censor their speech and avoid political engagement out of fear."
So, all in all, you can bar a foreigner from entering the country for whatever reason. Once they're in the country they have the right to say whatever they like, as long as it's legal. If they get arrested then that's a little different, for some strange reason, even if they don't get prosecuted.
If they say something that is a "national security threat" then they can be kicked out for it. However, these people weren't doing that at all. Trump is just being an a-hole.