Section 23. That the right of every citizen to keep and bear arms in defense of his home, person and property, or when lawfully summoned in aid of the civil power, shall not be questioned; but this shall not justify the wearing of concealed weapons.Most of us believe this means that a law making concealed carry illegal would be constitutional, not that one allowing concealed carry is unconstitutional. If the constitution was intended to prohibit concealed carry it should read "...but no citizen shall wear a concealed weapon.
Now the case is in the Missouri Supreme Court. If they find the Missouri Constitution forbids concealed carry, a lot of Missouri cops will have to change the way they carry their backup weapons.