Texas wouldn't be very smart to leave the U.S.
First, there would be a war. The American "corporation" is never going to let such a large territory slip away quietly.
Second, that same corporation would tank your economy, and convince it's allies not to trade with you.
It's a wonderful idea, but it wouldn't be pretty...
Texas never was part of the United States, but you are correct about the corporation, and Texas is actually under a military occupation by that corporation, but under their own international agreements they have to allow the people of Texas their own "political beliefs" and they cannot compel anybody to work for the government. The original Republic of Texas was actually put into abeyance (dormancy) in 1845 when Texas was alleged to have joined the union, and some people figured that out and brought it out of abeyance, and it is for that original Republic of Texas that the elections are for. There is a Texas Supreme Court case that the Texas Supreme Court turned away in the mid 1990's "for lack of jurisdiction", which is proof that they know that we are the lawful de jure government of Texas.
Wow, that just makes me want to move to Texas.