Corporation are people according to SCOTUS. Can finance superpack to spew lie , negativity, false information to Damage any opponent ( individual, groups, etc..).
False advertisements is also another way to damage a competitor.
And all this is legal, fair & balance...
But if a real citizen express personnel opinion ( real or bias ) against a corporation, that citizen can be sued an brought to justice.

I guess we have two kind of citizen( people & corporation ) with a different set of rules for each.

Just food for thought,