I bet if you think about it you can figure it out. Here is a clue...add the word "yet".
Texas nedded this to beef up funding for their dilapidated rail lines. That is now dead. New Mexico now has the ability to raise funds for it or get federal money. Abbot, again, cost Texas jobs and money.
None of that makes any sense.
First, Texas doesn't have "dilapidated rail lines." They don't have any rail lines at all. Rail lines are privately owned.
Second, do you think Union Pacific or some company that actually owns rail lines is going to spend hundreds of millions of dollars (or more likely, billions of dollars) to build new lines in New Mexico just because the Governor of Texas and the President of Mexico are in some political pizzing match? When was the last time you actually saw a new rail line constructed? I'm not talking about a few miles of street car lines like in the Twin Cities. I'm talking about honest to good rail lines, where you are driving across that countryside and thought, "huh, when did they put those rail lines in?" I'm going with "never." Not when they already have perfectly good, working rail lines to and from Mexico already in place.
Third, have you ever seen where trains enter the country from Mexico? This isn't like crossing the Canadian border in Pembina, ND in your '14 Camry. They have a giant, secure area, fenced in, well lit, where the trains are brought in and stopped. The Border Patrol then does a close inspection. Then the railroad security does an inspection. The frigging trains are x-rayed from front to back. Thermal imaging is then used. Finally, they run through the dogs.
You think they're going to set up one of these complexes on the border in New Mexico, a state that doesn't even have a town of 50 residents on its border, when they already have perfectly good security complexes (and people to work them) in actual cities elsewhere?
Here is what this smells like to me, although honestly I have no working knowledge of Mexican politics. This smells like a situation where the President of Mexico promised a "train to Winnipeg" (I don't know, maybe like a border wall), and is now going to use this to derail (pun intended) a plan that was never going to happen.