Though the outcomes of tinker and schenck differed, which best describes what these court decisions have in common?

I believe the answer is: speech of right must be limited in order for one's own safety and protection

For example, when a group of protester have a peaceful protest in front of government office on a legislation that they passed, their action is protected under the free speech clause.

But, when that very same group start to threaten to blow up the government office, then it considered as a threat and they are no longer protected under the free speech.