In what world is public opinion not universally against the cartels? It's hard to take you seriously after that.
I think you’re getting tripped up by some specific wording and managing to miss the point the poster was making. The point should be taken seriously even if imprecisely articulated. While most folks are against the cartels, there’s a much wider range of belief on how much they warrant government or military intervention and to what degree we should be spending various resources on them. The historical state of play was(is?) that cartels are criminal organizations which are generally a policing matter that has escalated to specialized policing agencies and multinational networks of policing agencies. The marked escalation of the military into this is a more recent piece that is somewhat more controversial. One doesn’t have to be “in favor of the cartel” to ask questions about whether our military should be bombing boats or invading countries to ostensibly neutralize organizations that historically have been subject to policing operations.
To go back to the parallel… the public wasn’t in favor of Al Qaeda before 9/11 either, but there was a huge difference in the level of response the public was in favor of after. It turned from an intelligence monitoring level of response into an active military invasion of multiple countries.