You said — “ok - then what happens? Does each state then get to vote on the new constitution? What if a bunch of red states decide to reject the new one and the blue states all approve? Van we then write our own and go our separate ways? If so, then I am all for having a constitutional convention, the sooner the better.”
Then what happens is that 3/4 of the states must approve the amendment (or each of several amendments, if it came to that) — in order to ratify the amendment. It hasn’t always been easy to get 3/4 of the states to ratify an amendment to the Constitution.
The question becomes can you find 13 states to reject a wild ammendment. Looking at the red/blue map we are probably OK for another few years, but the demographics, media brainwashing, and public school indoctrination system are all working 24/7 to finish the job.