We recognize that accepting homosexuality as morally right is not only against God's commands to us; we also know that it is not good for our society nor for individual people. But, we also recogonize that American's can decide that we will have a civil law that will violate God's law.
By disobeying God's law as a nation, we move ourselves away from being blessed by God, and toward God's judgment and wrath.
God is patient. God always give humankind plenty of time and many opportunities to show Him whether we will obey Him or Satan. For example, in Genesis chapter 15 God is telling Abraham that his descendents will be given the land of Amorites, but it is not time yet because the current occupants will have more opportunities to turn to God. Meanwhile, Abraham's descendents will live in another land: "Then in the fourth generation they will return here, for the iniquity of the Amorite is not yet complete." (Genesis 15:16 - NASB) The Amorites then had about 500 years to start obeying God--but they didn't and Abraham's descendents returned to drive them out of the land.
God is patient with America also. If as nation we turn away from God next week, nothing may change. We may not see the result of our action for hundreds of years. On the other hand, as America moves away from God, He may withdraw His blessing (or part of His blessing) from America--and then we start wondering why civil society seems to be breaking down.