Texas Republicans, who just lost their bid to have the Supreme Court overturn the legitimate results of our recent presidential election, talk constantly about secession. They call it #Texit.

In 2009, at a tea party rally where his supporters chanted, “Secede! Secede!” then-Texas Gov. Rick Perry suggested his state might consider leaving the union. “If Washington continues to thumb their nose at the American people, you know, who knows what might come out of that?” Later, he said he was joking.

But just this week, a Texas state representative announced he’d file a bill that would allow a referendum on secession. This would be a symbolic vote only. After the Civil War, in a case out of — where else? — Texas, the Supreme Court ruled that no state can unilaterally secede.

Seems sort of, I don’t know, treasonous to advocate breaking away from the union.

But most people don’t get too worked up about it. After all, the phenomenon is part of the American DNA, said journalist and historian Richard Kreitner, who explores the issue in his new book “Break It Up: Secession, Division and the Secret History of America’s Imperfect Union.”

Think about it: “George Washington was a traitor to his country,” said Kreitner. “The American Revolution was a secessionist movement. We all have a tortured relationship to secession because the country was founded on the act of secession and this is why it’s always an available option.”

Secession, he said, “is an expression of nationalism, in a certain way. If you have strong opinions about what the country’s purpose is supposed to be, you are the most stalwart of patriots, but the moment it’s not going your way, you turn against it. That’s what we are seeing with people like Rush Limbaugh, who were patriots until they weren’t.”