> "Some political organizations should be prohibited."

And who gets to decide which ones are prohibited and the standards used? Because some people think Antifa should be prohibited while others think it's a necessary organization that is fighting the good fight. Some people think Christian organizations that reject homosexuality and gay marriage should be banned while others think they are doing God's work.

Thats why it's necessary to protect all viewpoints when talking about speech. Because your opinion is not the only valid one.