1. I think that the war on drugs is a stupid and harmful waste of time and money. As long as Americans want drugs, they will get them one way or the other. We should focus on social cures; treatment and prevention. To blame the public health issues of Americans on poor migrants is ridiculous.
It's not a question of blame. It is economics. You have a product that sells for $100s or maybe $1000s per ounce and then you have a plethora of poor agricultural workers available in central and south America for every possible aspect of making and trafficking it, including getting paid to migrate without carrying any contraband just for the sake of acting as decoys and distracting police from the actual mules.
I'm sure many of the people recruited to perform this labor would be just as happy or happier to work in a factory or produce cultural products or do something else, but they have bosses who know what sells and those bosses are cracking the whip to get that stuff across the border and into the hands of the people who are paying so much for it.
2. I fully support efforts to combat human trafficking. Making it easier to cross the border legally is part of this.
You don't think more open borders makes it easier to covertly pimp girls (and boys?) from wherever to wherever? In a way I can see your point, e.g. tracking legal migrants is easier than trying to catch people who sneak across, but I think if you have large legal traffic across borders, it also makes it easier for the contraband and exploited/trafficked people to slip through.
The real solution is to reform the general population(s) of the world to stop abusing migration and trade to exploit each other, and until there is widespread cooperation in such reform, to maintain strong borders as one tool/weapon among many against exploitation.
3. We should deal with this current "caravan" in a humane way. We should treat them as fellow human beings in a difficult situation. We should meet their needs, and provide an orderly dignified process to decide their asylum claims.
I agree, as long as there aren't people taking advantage of kindness for weakness. This is what generally happens with anti-authoritarian people. E.g. spend a day observing kids misbehave in a classroom and you will see all the strategies kids learn from the popular culture about how to rebel against and defy 'the man.' There is so much lying and deceit among people who are able to simply turn off their consciences when they believe they are dealing with 'the enemy,' and they have been conditioned to see police and the US government as 'the enemy.'
4. These immigrants are no different than earlier immigrants (Irish, Italian, Asian). Calling them "invaders" or "mercenaries" or anything else is wrong. Of course, throughout history we have done just that.
No, that is a propaganda campaign of liberals to portray them in relation to citizens' ancestors who were immigrants. It's a brilliant ego-sell to take people's pride in their grandparents and use it to pull the wool over their eyes about global organized crime.
In fact, you're right though. Organized crime was also a thing during periods of past migration, and something like alcohol sales during prohibition would have created a huge amount of GDP to fund jobs for migrants. This is, I think, part of why liberals are so morally relative, i.e. because they figure if it makes money and creates jobs, we should just tolerate it. But growing GDP with things like drug sales and other 'pork barrel consumer spending' adds no real value to the economy, drives inflation, and ultimately causes social-economic damage due to dependency (physiological and economic) and in other ways.