candidate Rick Perry once suggested? Probably not. Can Texas split into multiple states pretty much whenever it wants? Yes, absolutely—and, most Texans of the 19th century assumed this would happen. The question was not "if," but "when" and "how." There were multiple plans introduced into the Texas legislature over the years, some for two Texases (or is it Texi?), others for three or four. One proposal that got introduced multiple times is shown in the map above. In its most-recent iteration (1870) it was called the Beaman plan and divided Texas in three: Jefferson in the east, Matagorda in the west and Texas in the middle. The proposal didn't get enough votes, but Texans kept trying. (Several of the plans are described—with maps—in Lost States)
Now that Rick Perry is officially in the presidential race, I wish he'd clarify his statement about secession. He might be a great potential president; he might be a lousy one—I have no way of knowing. But I do know that the jury is still out on his command of American history and geography. The right to split into multiple states is explicitly true for Texas, although it's also true for any state. While Texas has never split, Massachusetts has—creating Maine. Virginia also split, creating West Virginia.
But the topic of secession (that is, leaving the US) is more tricky. The last time any state tried it, a civil war was triggered, and we all know how that turned out. That said, historians and scholars like Thomas Woods point out that secession isn't actually unconstitutional. The whole thing is a lot more nuanced than you learned in elementary school. Rick Perry might actually have a command of this stuff... or he might have it all wrong. It's not clear just yet which one that is.