No, but their owners should as a matter of free association, which amounts to the same thing. The SCOTUS "decision" (Santa Clara v. Southern Pacific) recognizing the equal rights of corporations as "persons" was totally bogus. Hence, the legal tension between these collectivized rights as a "person" v. individual rights is a matter best left to natural law competition among the several States. That decision effectively nationalized control of that tension to Congress, which has played the great game like a fiddle. It is why the Republican Party chases big money at the expense of its conservative base.
Citizens united=bad
Unions=good