We're among the least protectionist -not to say we are not protectionist, but comparatively. Others have set the precedent for us. They need no examples or encouragement.
A smart foreign propaganda news outlet doesn't simply censor everything that makes their sponsor country look bad. You can push a worldview while still reporting most of the same stuff any other outlet would, and having actually-decent coverage means more people will tune in—then you save the heavy-handed slanted coverage for when it really matters.
Hell, look at something like The Economist. They're regarded as an excellent news source, which makes their efforts at pushing a certain economic and political POV far more successful than if they pushed it so hard that they weren't a good news source.
That said, yes, the 1A implications are thorny.