The correct answer is the Texas Legislature
The Texas legislature deals with drawing districts in relations to the membership to the United States Congress. Governors and the Supreme Court of Texas do not deal with this, nor does the federal government. They can however inspect whether or not it's been done correctly, but they don't draw the districts.
It gave them more power because before they didn't have much power.
It was the election of Abraham Lincoln as US president that caused southern states to secede from the union just weeks after it happens, since he was an outspoken opponent of slavery.
