There's precedent on this specific issue. The American Civil War was partly fought over the right of states to secede from the USA. But with the USA's triumph over the CSA, the constitutional question of secession from the Union was resolved and made clear and In the words of President Abraham Lincoln, "The Union of these States is perpetual!"
Now there's a growing movement called Calexit, which has spawned due to anger in California over the upset election of Trump. Many Californians may detest the Trump Presidency and many Americans may dislike California and its liberal policies, but it shouldn't mean that they should put the integrity of the union in peril.
So, we the American people implore Congress to prevent the secession of California from the Union, if it were to happen.