The words "choice" and "privacy" are used by liberals/leftists as code words that really mean something else to them.
"Choice" means "killing unborn babies" and "privacy" means "promotion of sodomy" or even "sodomy on the street/in the park/at the beach/in the public toilet".
Real choice and privacy - within legal and philosophical limits as delineated in the Constitution - is vital. But leftists don't mean real choice or real privacy. They're just codewords to them.
You are correct, the culprits in misusing the terms are the leftists; I must be in a dense mood tonight, of course "pro choice" means pro abortion - not much choice for the baby (whose body, through fantastic mental contortion, is considered to be a part of a woman's body) is there?
I actually have strong libertarian feelings and ideals, but also am a respecter of traditions since most exist for good reason (such as preservation of family), so I tend to have mixed feelings on some of these issues.
I'm not too sure that the Constitution delineates privacy or choice, except through its negative nature, which does not give central authority over such things to government.