Here’s a true story. Many years ago, in the mid-1990s, I was involved in a tech start-up company. The founder brought in a venture capital guy to seek funding. Mr. Venture Cap once spent a long afternoon regaling us with the story of how he & his pals secretly laundered millions of dollars in foreign money, through Liechtenstein, for the 1992 Bush campaign. (Yes, money from foreign states and companies flowing in covertly to influence a US election; imagine that!) He made it clear this was just routine procedure; he wasn’t bragging about the act of smuggling foreign cash into the electoral process itself – the boast was how MUCH he’d brought in, how good he was at it.
Of course, anyone interested can read of similar efforts throughout modern US history. The well-documented, far-reaching efforts by the UK in 1940, for example, to skew the field for pro-British, anti-isolationist candidates (not just with money, spying & media manipulation, but also with several notorious “honey traps” for leading US officials); or efforts to influence elections and policies by Nazi Germany, including big cash payments to some US Senators and passing money & intelligence through stateside corporate allies. The covert electoral interventions by Turkey, Israel, the Saudis, the old-time “China Lobby,” among others, are likewise well-attested.
The fact that this is a common practice that’s been going on for a long time (including the continuous, massive “infringements of national sovereignty” that the US govt has made in elections all over the world for decades) doesn’t mean it’s good. And it won’t be good if it is ever proved that Russia followed this time-honored practice in 2016. But I do think it would be better and more productive for everyone to quit pretending that foreign attempts to influence US elections (and vice versa) are some kind of unprecedented horror that has suddenly hit the nation like an asteroid from outer space. They're not.
But we can’t deal with the actual, endemic problem — which is part and parcel of the larger problem of an electoral system that depends on big money and partisan control of the voting process — if we can’t see it clearly. And if you think it will end if they finally find that video of Putin handing Trump a bag full of rubles, you’re in for a surprise.