When it comes to states rights, no one supports them more than conservative Republicans.
On Marriage Equality alone, the major objection to the SCOTUS decision is that the rights of American citizens should be up to the vote of the people on a state by state basis.
So you would assume that, agree with the state or not, the conservatives in the Republican Party would respect what the people of a state votes for in that state.
However:
Just this past week, New Jersey Governor Chris Christie, who has long opposed recreational marijuana, announced that when he is elected president,
“If you’re getting high in Colorado today, enjoy it, as of January 2017, I will enforce the federal laws”
Colorado, along with Washington, Oregon, Alaska, and the District of Columbia, has voted to legalize the use of recreational marijuana.
States rights.
Christie believes, “If you want to change the marijuana laws, go ahead and change the national marijuana laws”.
Apparently, national laws trump states rights if you do not like what the state has chosen.