The idea that foreign influence campaigns on American voters should be stopped is just a slightly disguised version of the idea that American voters have too much free speech and too much democracy. Which is a defensible position (I don't currently agree with it, but it's defensible), but I wish that the people who call for stopping foreign influence campaigns would just come out and state that this is indeed their position. Then we could have an honest conversation. They could, for example, argue that American voters are on average too ignorant, too stupid, or too prone to vote in destabilizing ways to be trusted to have free access to information. Or they could take it further and just plain say that we should limit who can vote or what can be voted for so that our politics stays within a given "acceptable" window. I would argue that whatever the American voters' tendencies might be, in the current political climate at least, I still prefer free access to information. Would I still value free access to information over keeping voters a certain "safe" way if it meant that some people would get elected who would actually put me in a concentration camp because of my political opinions or ethnicity? No. But we're nowhere close to that, since America has strong norms of civil liberty, so even people who want to put others in concentration camps because of their political opinions or ethnicity have a tough uphill climb if they want to actually do it.

In any case, I just find arguments that are along the lines of "it's not really free speech restriction, your free speech isn't restricted by not being able to see foreign propaganda" to be beneath contempt.

Personally I want to be able to see even foreign propaganda that is false. But attempts to curtail foreign propaganda lead to situations where even foreign propaganda that is true would be curtailed. And that is even worse. If some foreign government hacks the US government and dumps a bunch of compromising information about US politicians online, you'd best believe that I would like to see it.