Think a bit lower on the hierarchy, such as police and federal agents. But you are damn right the government should actively defend free speech, especially when it's the First freaking Amendment of the Constitution; of which the United States government is based upon. If the state refuses to defend one part of the Constitution from oppressive forces then the whole thing is potentially irrelevant. History shows this is how governments fall to tyranny.
I fail to see where I'm stating that the state should oppress one group's speech for the benefit of another. I said no such thing.
So, here it is again:
What if the state actively ignores one group's illegal activities (that have nothing to do with speech, such as harassment or violence), that are done solely for the purposes of oppressing another group's ability to exercise their First Amendment rights? At that point the state is complicit in the oppression and is becoming an oppressive state.
I guess for me it's the "active" defense of the First Amendment that concerns me, because depending on what that means it could easily be actively abused in exactly the ways that we're discussing through inactivity.
For this, I think other laws, assuming they're fairly applied, are sufficient and less open to interpretation.
The above comment points out that the government has a responsibility to fight people who break other laws, e.g. Murder, vandalism, harassment, etc.
It sounds like your suggesting that these are not enough, that the government should actively pursue those who have not yet committed a crime against someone's body or property, but instead at the point where they are actively threatening (by some definition of that) through speech.
Which by this definition, they would be utilizing their freedom of speech to do... which I think your implying the government should actively suppress. This sounds like it could easily be abused to fight any criticism of any group.