Millions of dead Vietnamese.

In any case that was a war against a hardened, experienced, determined enemy fighting for its freedom from any form of colonial occupation, both as a formal military and as an insurgent force in South Vietnam.

I scarcely think the Mexican population would rise up in defense of the cartels here.

A non-aligned population will look out for their own interests and are aware that the attention of the US is temporary but the cuadillismo that lead to cartels are a durable cultural artifact.

  The Battle of Culiacán, also known locally as the Culiacanazo and Black 
  Thursday, was a failed attempt to capture Ovidio Guzmán López, son of Sinaloa 
  Cartel kingpin Joaquín "El Chapo" Guzmán, who was wanted in the United States 
  for drug trafficking.
  
  Around 700 cartel gunmen began to attack civilian, government and military 
  targets around the city, despite orders from Ovidio sent at security forces' 
  request. Massive towers of smoke could be seen rising from burning cars and 
  vehicles. The cartels were well-equipped, with improvised armored vehicles, 
  bulletproof vests, .50 caliber (12.7 mm) rifles, rocket launchers, grenade 
  launchers and heavy machine guns.
https://en.wikipedia.org/wiki/Battle_of_Culiac%C3%A1n

I think a lot of people would be cheering on the destruction of the cartels.

They'd probably quickly stop cheering as their own homes and families were destroyed as collateral damage, which is what would happen if the "full force of the US military" were deployed against the cartels.

The last time America invaded Mexico City it created martyrs. It's a fascinating story that they do not teach at US highschools lol.

Curious, because the martyrs were Mexican high-school students.

We were briefly greeted as liberators in Iraq too.

The destruction of cartels would involve careful policing and corruption controls, the best American administrations have been bad at this. The worst... can barely put its pants on much less dismantle foreign organized crime. You can't shoot a missile at a cartel and poof it's just gone.