He twice stopped Hillary Clinton, the first time directly, the second time indirectly by sabotaging her with the FBI.
He forced Americans to experience a taste of the misery of living under Socialism, but without ever actually instituting it. It doesn't take a lot of that to convince any sane person that Socialism has to be stopped by whatever means possible.
He was lousy at working with the Congress to pass any of his agenda, which means that most of his ideas remain just ideas, locked forever in his head, and not into law. Most of what he did can be easily undone by executive orders, and 0bamacare was doomed to die an unnatural death anyway.
He got tens of millions of Americans to arm up even more heavily than we already were, and helped the gun companies and dealers to prosper.
All of the things he did caused America to vote for Donald Trump, and right the direction of the country. I say he's an American hero, to be celebrated forever more. Let's give him his own holiday.
Of course, I suspect that none of the above is what he actually intended, so perhaps he shouldn't be given so much credit.
Oh, and I forgot the most important one, which is the point of the original article - he was almost singlehandedly responsible for causing possibly irreparable harm to the Democrat Party, perhaps his most glorious achievement.