You can call them "civil unions" and play word games, but it's just gay marriage by another name.
A rose is a rose is a rose...
(and yes, I fully understand the irony of using that phrase...)
OK, that is your opinion, but inaccurate, because, beyond the symbolism (and symbolism matters) inter alia civil unions do not have certain monetary federal benefits that marriages do. I suspect there are differences at the state level too, in most places, as to the range of rights and responsibilities. In any event, it would be helpful to use the correct term, not the tendentious and inaccurate one. THEN one can argue, for or against, that they are fungible terms.