I know that most Americans do not know much about Mexican history, so here is a short lesson. Spain claimed most of the Americas as a result of Columbus' discovery which included all of Mexico, Texas and California. The first Spanish town in California was San Diego which was settled about 1610, before the Pilgrims came to Plymouth. This is to put some of the early history into perspective. Next is my history lesson.
Both England and Spain had exactly the same strategy when it came to their claims in the New World. I forgot to mention France in all this. They too had a large claim in North America. Now the problem that faced all these countries, how to enforce their claims? It is one thing to put up a sign that they owned this part of North America, yet it was another to keep other out. Remember that the Native Americans were here first and they all had to take the land away from the Native Americans. As you can see, it would take a very large army and a lot of money to maintain a claim on such a large area and that was the real problem, so how did they do it?
They gave the land away free to people from their home countries who would settle here. How could anyone turn down free land when they were virtual salves back home? With the free land, the settlers swarmed all over North America. This was just the first step. Once these settlers cleared the land and put down stakes, they owned the land and no one could take it away from them. It did not matter that the land was originally stolen from the Native Americans. These new settlers would fight anyone who tried to take their land away. Starting to see where this is going? Spain, England and France did not need to send out the army to protect their land claims, simple farmers who go the land for free did all the fighting for them. Great system or what. Other countries did this same thing too. Russia did this when Stalin stole the land from the people of one area and gave it to his supporters. This is how the Jews took over most of Palestine too. I think you see how it is done.
Now Mexico and California. For over 200 years, California was part of Mexico and everyone was happy with the arrangement, but things changed. Thousands of illegal immigrants came into California from the USA and other places until they out numbers the Mexicans who had lived there for over 200 years. When the illegal immigrants were in the majority, they decided that they would rather be a part of the USA rather than Mexico. If they had our "PC" mentality, they would have had a simple vote, but those were the days before "PC" so they had a short war that Mexico lost. California became an independent country for a few days as the "Bear Flag Republic" who then joined the USA in 1850. The discovery of Gold may have a had a little to do with it too, this is not the end of the story.
What do we have now going on at our Southern border? We have illegal immigrants coming into California in such numbers that, if it keeps up, will out number the legal citizens of California. When that happens the "PC" people will have a vote to return California back to Mexico and the USA will again be without California and its star on their flag. How could anyone be against the majority, even if it turns out to be by just "one" vote? We got Obamacare by just "one" vote, so why not California and Texas by "one" vote?