Mainly I think it was a communist plot. The idea was to undermine American values in universities, and then Americans themselves would destroy it from within. Most people I know don't think the KGB had that kind of influence. But first of all the KGB was highly compartmentalized. And the part of it devoted to disinformation in the USA would not have been known to other department people. Also, I should mention the budget of the KGB for these kind of operations was enormous. And once you have gotten to people in collage and convinced them of the "truths" of socialism, then even when they becomes senators or judges or even the president, they continue with those same policies.
Today the KGB is gone, and I doubt if Russia has the same goals as the USSR. They might want an expanded Russian empire, but I highly doubt if they are interested in the downfall of the USA.
Today the main threat against the USA are Muslims, but they are not the only ones. The Democrats are hard at work undermining the basis of the USA in other ways.