Any thoughtful person is going to realize they have a better chance of reforming our government than trying to establish a new nation. Any state that successfully seceded would immediately become a haven for every enemy of the U.S.
That is the right question. As others have suggested, "can they" is a question to be decided by the leadership, or perhaps by force of arms if the socialist in our White House opposes the decisions of free men. "Should they" is a question that has to be answered first.
I do not think that time has come, yet, but I would still cheer if a conservative state left in response to the excesses and usurpations of the thugs who have taken power in our country. I would pray for the success of any state or states that left. I might even move there if they wrote a good constitution ... something like ours but with the line "and we really mean it" after each of the first ten amendments, or whatever it takes to convince lawyers and totalitarians that written laws have meaning.
How do you figure that? Texas is to the right of the U.S., what enemies do you think that they would become a haven for, Californians, New Yorkers, the Democrat party, Now, ACLU, NEA, Acorn?