People who claim it is "ambiguous" don't think it through. The reason the US Constitution is silent about it is because a similar assembly had just written that independence is a right a mere 11 years earlier, and in 1787 no one had forgotten it.
The constitution didn't need to say anything on the matter because everything necessary had been said 11 years earlier.
You’d think that a nation born in secession from the United Kingdom would have taken that right as a given. Lincoln, like George III, turned an army on those who decided to leave.
If you compare King George III’s Speech to Parliament October 26, 1775 to Lincoln’s April 15, 1861 Proclamation raising an army to use against the states the difference is mainly George’s archaic and flowery verbiage. The content is the same.