"He said the tech-billionaire and Twitter owner, Elon Musk, would be elected to the White House to govern a splintered U.S. state, following Texas’ secession and its joining Mexico."
>>Welp. Elon Musk is not a natural-born U.S. citizen and is therefore ineligible to be POTUS. Sad! Sure, the Constitution can be amended, but it's fiendishly difficult to do so, unlike in Russia where the rubber-stamp parliament can easily do things like removing constitutional obstacles to Putin being President-for-life. Medvedev clearly needs to take a class in comparative constitutional law.
>>As for Texas leaving the U.S.: Texas has been independent and indeed a part of Mexico in the past. There's precedent! Texas is large enough to certainly be a viable, if diminished, independent country. That said, the pesky U.S. Constitution gets in the way again: state secession is simply unconstitutional. (See: Civil War). So, Texas would have to shoot its way out. Could it do it? Perhaps in an America that's as hopelessly splintered as the U.S. was during Civil War times, but that's doubtful. Beyond that, anyone who thinks Texan Republicans (the group most loudly posturing in favor of Texan seccession) would ever leave the U.S. to join up with *Mexico* simply hasn't been paying attention to those same Republicans' rhetoric on the southern border.