> Doesn't the first amendment apply to citizens of the United States and not to hostile foreign agents?
It was supposed to apply to every US person, regardless of citizenship. For non-US persons it's a bit theoretical since there's no real way to prosecute anybody outside the US, but activities protected by 1st amendment for a citizen still shouldn't be a base for prosecution by the US government, even against non-citizen. But it turns out that if you declare someone "hostile foreign agent" - on basis as strong as "criticizing Hillary Clinton" - it no longer applies. I am, frankly, extremely scared of the power of the state security to prosecute any non-citizen for as little as publishing an opinion about US political matters.
And if you remember what happened to surveillance - which was sold as applying only to non-citizens with extraordinary safeguards applied if a citizen happens to be involved, and turned out being routinely applied to citizens as a course of matters, with very little resistance or oversight - I don't see how this could not be extended to citizens too.
But even if it's not - does it mean any non-citizen immigrant which speaks for immigrant rights, or supports DREAM Act, or opposes Trump on immigration policy, or does any other political activity, can be declared a criminal now? Have you thought through which exactly powers you are supporting giving the state and how these powers can be abused?