So your argument are; that because Americans illegal immigrated into Mexico, took over a border territory, started a civil war and seceded, Mexicans should be allowed to illegal immigrate into USA...
I'm sorry that's a incredible bad argument, which will not convince anybody, and I mean anybody, in fact it may even make people support large scale deportation of illegal aliens, it's so bad.
I was't really making an argument, was just pointing out that a lot of Texans were illegal immigrants to Mexico, the irony.