" Let local jurisdictions set rules for behavior."

No... absolutely not. 'Behavior' is very different from laws about public safety or taxes. Opinions that are based in religious tenets or cultural generalities that do not limit your freedoms should never be subject to voting or political whims.

If you don't like abortions, don't have one... if you don't want to marry someone of the same sex, fine. It makes no difference whether 'marriage' was usually between a man and a woman. That is not a 'definition', no matter what conservatives would like it to be!
To 'marry' is to unite. It simply formalizes what has for eons been done informally- the sharing of home and responsibilities. NOTHING ABOUT gay marriage interferes with YOUR rights.