The South was actively resisting the Federal Government in the 3-4 year lead up to the Civil War. In a sense, it was a rebellion, just not quite the open war it became. We are in the same situation now. Dim politicians are actively encouraging rebellion against existing Federal Law and Law Enforcement. It is not protest, it is defiant rebellion, and yes, there is a huge difference.
From the text of the Declaration of Independence (emphasis mine.)
". . .We hold these Truths to be self-evident, that all Men are created equal, that they are endowed by their Creator with certain unalienable Rights, that among these are Life, Liberty, and the Pursuit of Happiness—-
That to secure these Rights, Governments are instituted among Men, deriving their just Powers from the Consent of the Governed, that whenever any Form of Government becomes destructive of these Ends, it is the Right of the People to alter or to abolish it, and to institute new Government, laying its Foundation on such Principles, and organizing its Powers in such Form, as to them shall seem most likely to effect their Safety and Happiness. Prudence, indeed, will dictate that Governments long established should not be changed for light and transient Causes; and accordingly all Experience hath shewn, that Mankind are more disposed to suffer, while Evils are sufferable, than to right themselves by abolishing the Forms to which they are accustomed. But when a long Train of Abuses and Usurpations, pursuing invariably the same Object, evinces a Design to reduce them under absolute Despotism, it is their Right, it is their Duty, to throw off such Government, and to provide new Guards for their future Security. . ."
Text of the First Amendment to the U.S. Constitution:
"
Amendment I: Congress shall make no law respecting an establishment of religion, or prohibiting the free exercise thereof; or abridging the freedom of speech, or of the press; or the right of the people peaceably to assemble, and to petition the Government for a redress of grievances."
Neither the Founders nor the secessionists chose to abolish either the British or American government. But both objected to oppressive taxation. Even a tea tax they might have accepted from their own representatives but not from Parliament where they had no representation. And yes, the seceding southern states pushed back hard on a system that put 75% of federal taxes paid on them as well as other laws they believed violated the constitutional principles of state's rights. Their protests however, while constitutionally protected, did not involved acts of domestic terrorism or any other violence that the modern U.S. left is now using. They just wanted to be able to determine their own destiny. Their ultimate protest--secession--was initially done peacefully and I believe would have remained peaceful if the North had not forced them into war.
There is ZERO constitutional or any other legal justification for the acts of domestic terrorism, arson, vandalism, breaking and entering, assault and battery, blocking streets, roads, bridges, endangering the general public etc. that current leftists in the U.S. utilize to get their way. I suspect in most cases it is because truly evil people will use any excuse to behave that way and/or to promote, condone, defend it.
Again it is a valid debate whether U.S. States have or should have the right to secede. But that I just can't see as the same thing as domestic terrorism, violence, pure evil by people who demand their way or they'll hurt you