Would someone please explain this Russian collusion thing to this Iowa boy?

[mac]

So it seems most all I hear about Trump from the progressives, liberals, and outright Trump haters, is that he colluded with the Russians. Still not even sure what the definition of collusion is. But here is what I do know and anyone can look this up. When Hillary was Sec of State, she got approval for the Russians to buy 20% of our uranium production. Soon after that, the Clinton Foundation, that wonderful altruistic charity, got a $150,000,000 donation from a Russian group. And shortly after that, Bill Clinton was flown to Russia and paid $500,000 for a 60 minute speech. All the travel expenses were covered, thank you very much. Just what am I missing here?