I've thought about this before, too. I think it's a great idea, but not likely to come to fruition without a show of force. The Mexican government is so colossally corrupt, and the drug cartels/oligarchs are so influential that any attempt by America to encroach upon their territory would be met with unprecedented violence. It would require, firstly, an underground resistance to the current regime, aided by US weapons and supplies, with the promise of either a) a still independent Mexico with a new regime, or b) US Territory status with the option of statehood after the legal requirements were met. A tall order, to say the least.
That's an awesome idea. Crime in Mexico would actually be handled and stopped in Mexico, instead of spilling over the border. You are right about the property market too, real estate agents would have a field day. I would expect economic growth to skyrocket for Mexico and the other 50 states. I think the only real opposition to this plan are the corrupt officials in Mexico who would either lose financially or would end up on jail for their involvement in criminal enterprise.
I am from Alabama, and I am a big advocate for Puerto Rico Statehood. Check out my Chanel, i made a video about it. I have no problem with Mexico becoming states. Mexico is divided into 30+states. So that would give us 80+states. Thats a lot of stars on the flag lol.
But as long Mexicans swear loyalty to the United States, and the US flag. I say viva la Mexican statehood.