Being Negative about Obama (a negative) IS a POSITIVE- "double negative."

You're NOT negative when protesting or rejecting NEGATIVE "stuff."

It is a POSITIVE being negative about a negative.....just as your english teacher about a "double negative."

http://blog.oxforddictionaries.com/2012/02/grammar-myths-3/ 

Ask a Math person. ...it's SIMPLE math...

"A double negative occurs when two forms of negation are used in the same sentence. Multiple negation is the more general term referring to the occurrence of more than one negative in a clause.
In some languages, double negatives cancel one another and produce an affirmative sense; in other languages,