Foreign Affairs

Of course the russians (and chinese, israelis, etc.) buy access, buy propaganda outlets, buy power (legislatures and presidents).

Part of the problem as others have said is that the intelligence agencies (CIA, DIA, NSA, etc.) work apart from each other and from the enforcement organizations in the US (FBI, local/state). And we all know that some of these groups are also infiltrated. One good example is Gen. Michael Flynn at the DIA who is now known to be a russian operative. Or the head of the US Executive branch, Donald Trump who openly courts putin.

We all hope there is some behind-the-scenes magical organization working for only the benefit of Democracy who is keeping an eye on all of this and will swoop in at the last moment to save the day. (Un)fortunately, we do try to hew to the rule of law which, like democracy, can be compared to making sausage.