It was an independent republic before it was absorbed by the US.
No other state has this history.
Because of its unique background, Texas possesses a number of legal loopholes that makes it easier for it it to step away from the United States and go it alone.
Is this likely to happen?
Most people would say no. Then again in the 1980s most people, including people whose entire career was studying the Soviet Union, would never predicted its breakup into numerous independent states.
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