Earlier quoted context omitted.
Corporations are not people, and the Supreme Court has never found that they are -- this soundbite is a misunderstanding of Citizens United v. FEC .
They are people associating freely, however, which is protected under the First Amendment.
I believe current law is that people have the right to peaceably assemble only for the purpose of petitioning the government for a redress of grievances.
It sounds wrong, but there it is.