Of course I would defend Texas you unamerican commie lowlife! REMEMBER THE ALAMO!!!!
The actions of Mexican military forces within the disputed boundary lands north of the Rio Grande on the Independent Nation of Texas which joined the USA constituted an attack on American soil. Texas declared independence, they actually had independence and joined into a Union with us. Just like the American Revolution, this was valid.
The territories of New Mexico and California were only nominally Mexican possessions with very tenuous ties to Mexico. The territories were actually unsettled, ungoverned, and unprotected frontier lands, whose non-aboriginal population, where there was any at all, represented a substantial—in places even a majority—American component. Moreover, the territories were feared to be under imminent threat of acquisition by America's rival on the continent, the British. So Mexico lost lands, it wasn't actually governing or protecting and were populated mostly by non-Mexican aborigines and actual ethnic American immigrants that they themselves invited there because they had no population. Sorry those American's didn't make good tax slaves for their Mexican overlords.
So no, USA didn't steal their land. First we conquered it in a just war, then took the mostly unused land and put it to use under the Lockean homestead principle.
Meanwhile you are still robbing us of our tax dollars to put a lowlife scumbag in a luxurious retirement when all he really deserved is to dangle from a rope for being a goddamn communist and incompetent bureaucrat who mismanaged our fisheries. At the very least you could apologize for being a worthless parasite your entire life then never show your face in public, speak in public, or post your drivel on the internet again.