It is corruption if a president lets campaign contributions influence their choice of appointees to political positions. Whether or not Obama did that is another discussion, but just because Trump will do the same, we should not hold any other president to a lesser standard.
I actually edited out a long addendum to my comment above shortly after posting it. I guess I should have kept it because it addressed what I felt was the implicit assumption of the comment I replied to, and the less subtle assumption of your comment -- that because someone is criticizing a Democrat that they must be a Republican or Trump supporter. While statistically that may even be likely, you should withhold judgment at least until that person says something false or frames the discussion in a biased way.
I can't tell you how many times both online and in real life that people have made that assumption about me when I've criticized Obama, Clinton or other Democrats, or vice-versa when I've criticized Trump. I can assure you that I detest Donald Trump too.
Ah. Point taken, then (I did apparently need this addendum, ha). I did make this sloppy assumption.
I do have a significant D bias. Obama was by no means a perfect president - I mean, my God, I have a long list - but Trump, as far as I can see, doesn't even know what "President" means. There are loads of Republicans who I think would have done a fine job. I liked Romney, I think Kasich would have done OK, etc.
That said, an ambassadorship is normally given as a sop, isn't it? It doesn't alarm me in the slightest that Obama may have "literally auctioned off" ambassadorships - because I don't see the harm done and, as I say, I was under the impression that this was business as usual.
But you have to see that calling out possible corruption in the Obama administration (which, as I said, doesn't appear to have harmed us in any way that I know of) in the present context is ... well, it looks like carrying water for what appears to be shaping up to be quite literally the most corrupt administration America has ever suffered.
Good thing Mr. Trump would never do that kind of thing, like with the Department of Education or something.