Obviously, the measure will not stand. An administration that will sue a state like Arizona for trying to enforce the laws it won't enforce can't have any qualms about using the same preemption principles to argue that the federal ObamaCare law trumps this new Missouri law.
Even so, it's a significant blow to the President, because it makes clear the breadth and depth of the opposition to what he and the Democrats have done. Keep in mind that Missouri has chosen the winner in every election but two since 1904.
It's a real bellwether state -- and politically, something of a microcosm of America. St. Louis (which has a more eastern flavor) and Kansas City (which looks west) are more liberal urban areas, while the agricultural communities in the center of the state trend more Republican, and the southern part of the state has a distinct southern flavor.
If President Obama and the Democrats were unclear about just how unpopular ObamaCare is, well, the Show-Me State has shown them. Good for Missouri!