Let me be clear once again. I'm not really concerned for the United States. I pray for the peace of Babylon. I live here. Some of my ancestors have been here since 1620. It's far preferable to live in a civil and orderly society than to live in crime ridden chaos. It's nice to be able to walk safely down a street and not be robbed or shot at.
As a Christian I desire a venue in which I can live my Christian life and an environment in which the gospel can work....one in which we can freely speak to others. A concept like the 1st Amendment is something we should desire and treasure. With it come many dangers and opportunities for others to do things that aren't desirable. Though it allows them to continue their lost behaviour it also allows us to bring them the gospel without persecution.
Theonomists have been pretty vocal in the past about the 1st Amendment. If you're committed to state enforced Sacralism...the 1st Amendment is an abomination. It grants civil protections to false religions and allows anyone to challenge what they hope would be the establishment.