[dragonwriter]

> This is just an attempt to get attention. States can't just decide to split themselves into multiple states, it requires federal legislation.

It requires both State action and federal legislation. But the State action is clearly a required step.

> The only state that can split itself up is Texas, which was part of the agreement to bring the Republic of Texas into the union.

As your own link notes, that agreement specifically cited that it could only be done subject to the requirements of the Constitution, which would seem to mean that Texas can do it exactly as much as any other state can -- that is, with action of the State legislature and the federal Congress.