This is a clear example of government-funded, political indoctrination. 

Via Ammoland: 

When political activists are attempting to pass a long-term agenda with emotion and fear, they cannot allow dissent. The emotional narrative they are pushing is fragile. Dissent causes people to think. Thinking causes the narrative to collapse.

Andy Dalsin, alone and courageous high school student, stood up to the organized political agenda of the left. He “spoke truth to power”. He was not allowed to protest with others of his school, but was driven off by the school principal, Lonnie Seifert. From, video at link:

Dalsin said principal Lonnie Seifert told him to give up a sign that read “Guns don't kill people. People kill people” or leave the property, citing district policy.

“I stood in the back,” he said. “I didn't try and cause a ruckus, but I was seen by the principal and he came and we had our exchange.”

The district said in a statement that “such items must be submitted to and reviewed by school administration at least 24 hours in advance.”

But Dalsin stresses other students also had signs, and told him they didn't know about the policy either.

“Administration didn't fairly use their policy across the board,” he said. “I felt like I was singled out unjustly and my constitutional rights and my First Amendment was trampled on.”

The New Prague High School administration put up an explanation of Principal Lonnie Seifert's actions. They claimed that they have an obligation to enforce their “free speech” policy without regard to political viewpoint. The jarring contradiction is the walkout only had one political viewpoint. Any others were suppressed.

Read more here.