Does a state have the right to secede from the Union of States?

Yes. States may - constitutionally - join themselves with other states at their will, and their involvement in the union should not be coerced. The Constitution could have stipulated the Union was to be perpetual and irrevocable, but it did not. Furthermore, the founders repeatedly argued that the agreement forming the United States was not forever binding, but only binding by the continued consent of the States.