I would have put this in the thread about B J but that was prematurely closed.
You can think, judge, and have any opinion you want; don't let anyone tell you otherwise.
This is not G Orwell's 1984, and there is no thought police.
Society does, however, have rules, and you cannot act on those thoughts, judgements or opinions in manners which are deemed illegal.
This site has similar rules of posting behaviour, which you agreed to, when you joined; maybe you should read those rules.
Oh, and if you expect others to respect your right to your own opinions, even those concerning B Johnson, you should then respect their right to have a possibly unfavorable opinion of you.