Actually Chris I thought Amendment 1 would also only affect statewide DP or civil union but that's not what the amendment says.
It says: "Marriage between one man and one woman is the only domestic legal union that shall be valid or recognized in this State. This section does not prohibit a private party from entering into contracts with another private party; nor does this section prohibit courts from adjudicating the rights of private parties pursuant to such contracts."
One reasonable reading of that language is that NOWHERE in the state can any entity recognize any other domestic legal union other than marriage for any purpose (they are not valid or recognized). It blows every local jurisdiction out of the water.
Honestly, I don't see how the heterosexual supremacist proponents of the measure they get over the 1996 Supreme Court case of Evans v Romer which overturned Colorado's anti-gay ballot measure that tried to ban local gay rights ordinances anywhere in the state.