Legal Question in Constitutional Law in Washington

It would be a violation for a government entity to deny a permit because it didn't approve of the protesters' message. Almost everyone who issues as such permits knows this. It is very rare for a permit to be denied due to the content of the proposed speech.

Large gatherings often require permits because they affect traffic, require extra police presence, generate extra trash, etc. Cities, states and other government entities have a legitimate interest in having this information beforehand in order to prepare for those impacts. The only legitimate reason to deny a permit is that the entity cannot deal with the planned gathering at the proposed place and time. This is true whether the gathering is a protest or not and, if it is, regardless of what the protest is about.