But you just admitted that a constitutional convention could throw out the constitution and write a new one. That is exactly what happened last time:
1) Throw out the old (Articles of Confederation)
2) Write a new one (U.S. Constitution)
3) Lower ratification requirement (from unanimous to 3/4 of states)
How do you prevent such a thing from happening again?
True, but read how the ratification works, all amendments to the current constitution agreed to at the Convention would have to be ratified by the states in one of two forms.....and that requires 38 states to ratify.....
So even if the convention approved an amendment that said 1/2 of the states could approve amendments, 3/4th of the states would have to approve that....