It's a fair question! That's how English works!

He didn't do nothing.

Another grammar Nazi! Love it!

The OM may not deserve a grammar Nazi, but it's definitely begging for at least a grammar cop.

I'm no fan of Trump, BUUUUUT I am going to pull you up on your logic theory.

If not A => not B
does not imply
A => B

HOWEVER!

If you had said:

"If you ain't for trump, you ain't shit

"Therefore it follows that if you are shit, you must be for Trump"

THAT is now mathematically correct.

Now you know why I hate math...….