A reunion would necessitate the concept that a vote follows property ownership, not citizenship.
I very much agree with changing our voting laws, so that only those who have an honest stake in the country, and who are contributing members, can vote.
As wonderful of an idea as it is, it's not in the Constitution. Doesn't mean that it shouldn't be. I personally believe that it was a terrible oversight by the Framers to not include that provision.
In a newly re-formed union, we should begin the reconciliation process with an improved basic charter. Two and one third centuries of experience have taught us much about the Constitution's strengths, and its weaknesses.
If a constitutional convention is to happen, I would not trust the blue states to be a part of it. I'd rather see it done by a confederation of red states during a period of time in which they're politically dis-unified from the blue states. After the blue states implode, and come begging for readmission to the real union, their first order of business would be to ratify and agree to the improved Constitution.