This is no longer the age of enlightenment.
This is the Age of Entitlement.
Better to try to elect leaders who will follow the old Constitution than expect that politicians in this day and age will meet together to create a better one. That ain't gonna happen.
If the Congress of the United States elects to have the ratification procedures conducted by conventions rather than legislatures, the method of selecting the delegates to those conventions would be chosen by the legislatures. If only 13 legislative bodies out of 99 object to the method chosen by the other body because it is considered to favor a leftist amendment, there is no ratification forthcoming from that state.
By either procedure the odds of a liberal amendment getting past so many conservative legislative bodies in so many states is both arithmetically and practically remote.
Finally, this is only the last line of defense, there are innumerable steps along the way which make a "runaway convention" virtually impossible and render the need for the states to fail to ratify very likely superfluous.
I'm willing to try, though. If they ignore the clearly stated amendments, then we'll try the ammo box.