If only it was JUST sowing discord.
Through the presidency, Russia's taken control of US foreign policy. The US is no longer "leader of the free world". It seeks friendships with and supports dictatorships. It is in the process of undermining NATO. It has abandoned its allies in the Middle East and given its Syrian bases to Russia. It has damaged its trade relationships with everyone except Russia.
Russia has also taken control of one of the US' two parties and is undermining the country's basic tenets such as the rule of law. It clearly also has the ability to disrupt and influence US elections.
Russia has influence over a considerable chunk of US media. And it has figured out how to appeal to a large chunk of the electorate.
Basically, the US is becoming the American Hungary, a country that looks like an independent nation but is to a great extent a Russian colony. The process isn't complete. But it's quite far advanced.
This isn't meddling. It's a takeover.