Congress, now obsessed by the notion of Russia and unable to think in long strategic terms, has acted in short political terms, believing that its stupid sanctions, which an angry Trump had no option but to sign into law, will ingratiate it with voters. In fact most voters are fed up with Russia, while a large part of the rest of the world is fed up and exasperated with America.
Europe is furious about these new strictures because they have the potential to interfere with its own dealings with Russia, in particular in the energy sector. The plain fact is that nothing which is of real importance to America can be achieved without Russian (and Chinese) cooperation. There is a new world dynamic out there which an ignorant Congress has failed to spot. What would be a real disaster for America and for the world would be a weakened and unstable Russia.
At the heart of this folly is the cultural belief in the impregnable integrity of America. Since the British were kicked out, no uninvited foreign foot has trod upon its soil, nor destruction fallen from the sky. Even 9/11, though planned outside, was organised and executed from within. So the notion that foreign hackers, whether or not government authorised, could attempt to swing an election one way or the other is a violation akin to rape of the very essence of the nation itself.
At least that is how the political class sees it. The people could not care less. They take such things for granted. That is modern technology, most of it invented in America. And there is another thing. The people hate the political class anyway.