I believe the Blue Laws (while wrong) are constitutional because the constitution does not bar them from much. Also I believe technically a state could constitutionally pass them. The reason being that the first amendment clearly states Congress shall make no law respecting an establishment of religion, or prohibiting the free exercise thereof; or abridging the freedom of speech, or of the press; or the right of the people peaceably to assemble, and to petition the Government for a redress of grievances.
The blue laws don't establish a religion or prohibit the free exercise thereof they only enforce the rules of one. You may be able to argue that enforcing the rules are a form of establishment and I personally would agree that it crosses the line and would never vote for them (either state or federally, I wouldn't even vote for them locally as I believe they do nothing of any value what so ever). That being said it is a government by the people and it is constitutional but a major step in the wrong direction.
Thoughts?