If you know "Past Tense" you would see I used (past tense) the word "used" (past tense) to be the abbreviation.  Your link is for the current 2 letter abbreviation which I am perfectly aware of.

The NY Times in 2015 or anytime is hardly the standard for accurate news!  Try this instead:  http://obamacarefacts.com/state-health-insurance-exchange/

Please give me the location in the U.S. Constitution which states any such separation!  

Have already supplied FACTS to you.  You just need to look at the links (which are not slanted!)