Convention of the States is not a bad idea. Shows his true Constitutional scholarship.
The problem is that our population today is so politically and economically ill-informed that the thing would turn into an unmitigated disaster.
Rights to housing, free tuition, jobs or income, health care, and who knows what else would surely emerge.
But politics is about what's possible, and further amending the Consitution is all but impossible now in our deeply divided country. It has only happened twice in my lifetime, and the last one took over 200 years to be ratified!