[Ken H]

Article IV, Section 2 deals with privileges and immunities, not rights. I said when it comes to Article IV privileges and immunities, a state cannot treat a citizen of another state differently than their own.

So what was in the Constitution in 1787 to stop a state from denying fundamental rights to a citizen of another state, if not Article IV?

[robertpaulsen]

"So what was in the Constitution in 1787 to stop a state from denying fundamental rights to a citizen of another state, if not Article IV?"

By "denying fundamental rights" of course you mean, "denying the protection of fundamental rights". In 1787, there was nothing to stop a state from denying the protection of fundamental rights to their OWN citizens (much less citizens of another state) except the state constitution.