Well, I would not agree that about poitical campaign and influence.
Firstly, one is politics conducted within a nation state by lawful actors. The other is a foreign adversary attempting to influence events in line with that country's policy.
For example, it is alleged the Russians go from "overt" (IE, what they churn out on RT), to Grey (IE, leaked via Wikileaks but favourable to Russian foreign policy agenda) and then the "black" (false profiles messaging on social media, to use of proxy online actores to attack political opponents).
As to critical nodes, it is waste of of time to adopt a "one message fits all". With the alleged theft of voter registration and other targeting data, an advanced persistent threat could well be in a position to concentrate upon a "critical node". What do I mean by that?
If a group were to accurately data profile these constituncies and likely messages, an attempt to support a preferred candidate could be made.
Which is what I understand the indictment of the GRU officers alleges.
I have not seen anyone credibily say what any impact has been. But that lack of certainty has more credibility than Trump's blanket "nothing to see here".
It's not just the Russians, here is a recent example of alleged behaviour from the Iranians.
Suspected Iranian Influence Operation Leverages Network of Inauthentic News Sites & Social Media Targeting Audiences in U.S., UK, Latin America, Middle East « Suspected Iranian Influence Operation Leverages Network of Inauthentic News Sites & Social Media Targeting Audiences in U.S., UK, Latin America, Middle East | FireEye Inc