The First Amendment to the US Constitution bars the government from infringing freedom of speech. There is no implication in the text that government infringement of speech by non-citizens is authorized.
A petition to deport a British citizen, Piers Morgan, for political comments he has made in regard to gun control in the USA is gaining signatures.
I urge people who understand and endorse the intent of the First Amendment and its prohibition of government controls on political speech sign this petition.
Signing this petition does not mean you endorse Piers Morgan or his comments.
It is a declaration that you endorse the First Amendment.