New York Gov. Andrew Cuomo says he’s discovered a way to kneecap the NRA by outlawing its gun-liability insurance program and is urging other states to follow his lead, saying they have a chance to exploit the gun-rights group’s admitted dire financial situation. Mr. Cuomo said the National Rifle Association let on in court papers last month how much it relies on the liability insurance program to bolster its bottom line, and could succumb to pressure. “I believe this insurance product is going to be illegal from a public policy point of view in most states,” Mr. Cuomo said on...