A common objection to the Supreme Court’s Citizens United decision, which struck down limits on political speech by corporations, is that corporations do not deserve First Amendment protection because they are not people. Cato Institute fellow Ilya Shapiro explains why that argument is so much nonsense:

[W]ould the “no rights for corporations” crowd be okay with the police storming their employers’ offices and carting off their (employer-owned) computers for no particular reason? — or to chill criticism of some government policy. 

Or how about Fifth Amendment rights? Can the mayor of New York exercise eminent domain over Rockefeller Center by fiat and without compensation if he decides he’d like to move his office there?

So corporations have to have some constitutional rights or nobody would form them in the first place.  The reason they have these rights isn’t because they’re “legal” persons, however — though much of the doctrine builds on that technical point — but instead because corporations are merely one of the ways in which rights-bearing individuals associate to better engage in a whole host of constitutionally protected activity.