What is a "runaway convention?"
A "runaway convention" is a fabrication promulgated by those who wish to maintain the status quo. They sow fear by suggesting that once an Article V Convention has been called, the delegates can propose drastic amendments like rolling back the civil rights of women and minorities, or even scrapping our Constitution altogether and writing an entirely new one. Their concern is not for the integrity of our Constitution, but in protecting the influence, money, and perks they enjoy because too much power has aggregated in Washington, DC.
There are two reasons we can be confident that an Article V Convention will not "run away." The first is the high bar of ratification: any amendment proposed at the Convention must first secure the support of at least half⎯perhaps more depending on the rules adopted at the start of the Convention⎯of the delegations present. It must then be ratified by at least 3/4 of the states. Neither party has controlled that many state legislatures in our lifetime. Just like those that originate in Congress, a state-proposed amendment must enjoy broad, bipartisan support in order to become part of our Constitution.
The other reason we can be reassured that a Convention is safe is that the states have met in convention dozens of times throughout our history. Nearly every state in the union is party to at least one interstate compact, many of which continue to meet regularly. There is no evidence that any of them⎯including the Constitutional Convention of 1787⎯ever exceeded their mandate.
Professor Rob Natelson's A Response to the "Runaway Scenario" is available here.