https://en.wikipedia.org/wiki/Russian_interference_in_the_20...
https://en.wikipedia.org/wiki/Russian_interference_in_the_20...
The example in 2016 of one particular country's actions is more about what the establishment chose to report for political reasons, although obviously there is some novelty in the way influence efforts are changing over time to adapt to new technologies.
Elections are won by people voting for issues that affect them, not a rich boogeyman
A good, obvious and well-documented example is that both British and German agents were spending millions to impact US elections in the WWII period. There are obviously today hundreds of lobbying groups dedicated to producing propaganda and swaying legislation in the US that benefits their country. Some of it is aboveboard, some of it is not.