Mexico’s cartels are indeed highly dangerous, but Mr. Trump seems to miss what makes the country’s organized crime networks such an enduring menace. In 12 years covering Mexico as a journalist, I’ve learned that force alone can’t take cartels down. The problem isn’t simply that drug-trafficking groups attack the state. It’s that they’re often a part of it. Like other political parties in Mexico, Morena, Ms. Sheinbaum’s party, has multiple high-profile members facing serious allegations of ties to organized crime. Fighting the cartels doesn’t just involve taking on drug traffickers. For Ms. Sheinbaum, it could also mean dismantling the foundations of local power in Mexico — and confronting members of her own coalition.