“Besides, didn’t Texas try this once already before it got whipped back into line by Abraham Lincoln and the Feds?”
Texas was an independent republic from 1836-1846.
They applied for admission to the United States but it took some years because of opposition within Congress.
One of the opponents to admitting Texas was Illinois Congressman Abe Lincoln.
Which is especially impressive when you consider that Lincoln wasn't even elected to Congress until 1847.