You make a lot of excellent points.
It reminds me of when I did some reading about the history of slavery in the US. We get blamed for the slave trade, but only 10% of the cross-Atlantic slaves came to the US - the other 90% went to the Caribbean or South America. Only 4 years after winning independence, the US Constitution was signed, putting a 20 year limit on importing slaves.
Mexico owned, but did not control, the part of the US where I now live for only 25 years. For over 150 years, the US has owned it and sought to control it...with significant success until recently.
And the difference between the US and Mexico isn’t that the US exploited Mexico. Mexico’s problem is that they have never adopted the freedoms and capitalism of the USA. If they adopted our culture, they wouldn’t have any economic reason to migrate here.
All true. And the important fact to throw back when they use the “the border crossed us” argument is that it is a lie. The Spanish who lived in the Southwest stayed, became Americans, and their offspring are Americans. The illegal alien invaders never had one single grandparent going all the way back who lived in the present SW, and was expelled. They are all invaders, period.