One of the skeletons in the Progressive Education closet is Scientific Racism, otherwise known as Eugenics, which the leaders of the Progressive movement enthusiastically espoused until the Nazis in Germany gave it a bad name.
It's not that the Left is "redefining" marriage — it's that conservatives must redefine the debate. The question in this debate should never be one of rights. It should be one of definitions. If we accept that marriage is, by definition, the union between a man and woman and nothing else, the faux-marriage-rights argument is moot.
When two white newspaper reporters for the Virginian-Pilot were driving through Norfolk, and were set upon and beaten by a mob of young blacks — beaten so badly that they had to take a week off from work — that might seem to have been news that should have been reported, at least by their own newspaper. But it wasn't.