Obama had a chance to put in a second Supreme Court Justice near the end of his second term, but decided it was too close to the election and wouldn't be fair to the democratic process

Obama didn't decide anything. The GOP had majority. They stonewalled his nomination.

Obama's mistake was to not give a forced 'thank you for your service, you deserve rest' to RBG when DNC had majority.

Did he really accomplish much, though? The only thing he did with his trifecta was passing Yet Another Tax Cut, with everything else either filibustered or voted down (ty Mr McCain). After 2018, his legislative agenda was DOA. He forced a shutdown over border wall spending, which failed. I can't think of anything else notable legislatively.

On the executive side, he managed to unwind some regulations (that were reinstated after Biden came in) and his FCC pick repealed net neutrality, but all of the super radical stuff he tried to do got tied up in the courts for most of his term and either struck down, reduced drastically in scope, or only took effect for a short while before he left office.

The biggest thing he did was packing the supreme court, but I would argue that's just as much due to McConnell, and any Republican president would have given us the same extremist court. All the stuff that's uniquely Trump, like the border wall or the Muslim ban, failed miserably.

You are absolutely right.

It's laughable that Democrats pretend to be powerless when they held the presidency and Congress for two years. I'm not a Trump supporter, but he was living proof that the president can (at least to a degree) achieve what they promise if they're willing to fight for it.

There were several good things he did for the wrong reasons, in fact, like pulling the US out of Syria.