My entire life, I've seen ad campaigns (TV, radio, web, etc) from American politicians; ads which are projected to a wide audience, and which are neither shy nor subtle about bashing their opponents.

I'm curious, how would others describe the line between acceptable influence (American political ads) and unacceptable influence (Russian political ads).

To be clear, I'm not saying there is no line, I'm just curious to read peoples' description of the difference.