Civil Unions/Domestic Partnerships/Anything ‘close’ to gay marriage are banned in the following states by constitutional amendment:
Virginia, Kentucky, Ohio, Michigan, Wisconsin, North Dakota, South Dakota, Idaho, Utah, Nebraska, Kansas, Oklahoma, Texas, Louisiana, Iowa, Alabama, Georgia, South Carolina, Florida
Here is the ones that have banned gay marriage, there are no talks in any of these for civil unions.
Montana, Nevada, Colorado, Missouri, Tennessee, Mississippi, Arizona.
That’s 26 states.
Wyoming, Iowa, Minnesota, Illinois, Indiana, Pennsylvania, West Virginia and North Carolina have also banned them via laws.
That’s 35 states.
Exactly what is your ‘most’ compose itself of? Only in the last batch could Civil Unions be brought forth, the others law is all so broad as to ban those as well, most ban domestic partnerships as well.