The 14th only gives equal protection... and with that an equality of rights, it is not an expansion of those rights... the equality has occurred with one man one woman matrimony. Its the same for each and every individual and gender...equal for all. So the hard sought perfect equality already exists. There is no way around, over or underneath the logic.
In any event, the power grab into a State's authority to determine for itself what its state desires in this regard is a travesty and, one would hope, the Supreme Court affirms the State's supremacy in matters of marriage. If the Federal Government does not stop this inexorable push for more and more power then, inevitably, we will have to have another fight about the proper way for a government to govern.
A society, its people themselves, can make its rules for how it wants its society to be. And then that can change, back and forth... this is not the USSR.
Polls are just a snapshot in time and are subject to speculation due to many factors, such as which questions are asked, how they are asked, which questions are not asked, who they are asking, blah blah blah... and here is an article that shows that opposition to SSM is understated in the polls Study: Opposition to same-sex marriage may be understated in public opinion polls | Pew Research Center