The editorial headline “Bottom Line: Russia didn’t interfere” does not conform to your statement “Kremlin hackers made numerous attempts.” Some estimates count 28 million attempts. You conclude they didn’t succeed. I hope you’re right. Who would believe a Facebook post that wrongly claimed Denzel Washington backed Trump for president? (per BBC report) I doubted online ads that showed Hillary Clinton arrested and staggering as if ill.
Some commentators say that millions of ads and posts were aimed at African-Americans, and since millions fewer of them voted in 2016 than in 2008 and 20012, maybe the Russians succeeded, somewhat. In addition, much propaganda was seen by other voters. Would anyone admit being deceived by any of it? The net effect, some say, is that many Americans are more doubtful of any political messages in any medium than in the past. This is an aim of a power that would undermine our democratic processes by demoralizing the voting public.
I don’t think anyone can be sure that not one vote was affected by this meddling. Whatever electronic protections, federal or state, are put in place before the 2020 elections., I hope voters will not believe everything they see in social media. But one must never despair that some will be important truth.