[DoodleDawg]

Texas has the right to break up into five states but not secede.

I don't think it has the right to even do that without the consent of Congress and the Texas legislature. That's in Article IV, Section 3.

[BuckeyeTexan]

I believe it is only the State of Texas that must approve the four additional states. Beyond that, any new state admitted to the union must adhere to the same requirements.