By now almost everyone is familiar with the term Brexit. The United Kingdom made history in June when it voted to secede from the European Union. But the United States is now faced with a possible secession of its own: Calexit. Some Californians are so upset about Donald Trump's impending presidency, they're threatening to break off from the rest of the U.S.

California plans to vote on its secession in the spring of 2019. "In our view, the United States of America represents so many things that conflict with Californian values," the California Independence Campaign states on its website. "Our continued statehood means California will continue subsidizing the other states to our detriment, and to the detriment of our children."

But is it even possible for California to abandon the rest of the states? Well, not unless the rest of the states have no problem officially saying good-bye.

While the Constitution doesn't specifically address secession, the Supreme Court eventually did. Thanks to the historic precedent of Texas v. White, argued in 1869, states are not allowed to unilaterally secede from the rest of the U.S. without the consent of the remaining states. The case dealt with the jurisdiction of Texas following the state's attempt to sue the federal government. 

"When Texas became one of the United States, she entered into an indissoluble relation," the Supreme Court ruling read. "The union between Texas and the other states was as complete, as perpetual and as indissoluble as the union between the original states. There was no place for reconsideration or revocation, except through revolution or consent of the states." The same principle applies to California's attempted secession unless a different Supreme Court ruling overturns Texas v. White.

California voted overwhelmingly for Hillary Clinton during the presidential election. Clinton won 61.5 percent of the vote compared to Donald Trump's 33.3 percent. Libertarian nominee Gary Johnson also received 3.2 percent of the vote.

California is far from the first to attempt to secede from its larger whole. Quebec has voted twice on seceding from Canada. The second proposal, the Quebec referendum, was voted on in 1995 and lost narrowly by a vote of 50 percent to 49 percent.

A petition circulated on the White House website in 2014 calling for Alaska to leave the U.S. and join Russia instead. Texas almost voted on leaving the rest of the states in May, falling just two votes shy of a vote.