Invoking Article V is extremely dangerous for the cause of liberty. I wouldn’t trust that progressives would be prevented from taking over a Constitutional Convention.
Each state would send delegates to the convention. How are progressives going to take over when they are significantly outnumbered. Second the convention is not dangerous even if they DID somehow manage to take it over. The conventions only purpose is to PROPOSE amendments and changes that then must be ratified by three fourths of the states. So do you really think the left has any chance whatsoever of getting liberty crushing amendments passed by thirty eight states? Obviously the left does not have a chance when it's put to the vote of the people in each state.
The left has always feared constitution amendments because they have never had the numbers to stop it. Have you ever thought about why a balanced budget amendment has never made it out of the congress to get voted on by the people? The answer again is obvious, because it would pass and the government would be forced to stop deficit spending. So what does the federal government do? It blocks the amendment so the people have no chance to vote. An article V convention takes the power away from the feds.
Lastly, the framers put in article V as a means to RESTORE liberty in the case where the government has become corrupt and refuses to limit itself. Do you think they were wrong?