I watched this last night and my jaw simply dropped. Rather than trying to summarize it, I'm just going to put the video here and let you watch.
TL;DR: Ross is the nexus between a Russian oligarch and Donald Trump. Possible money laundering and more.
We must have an independent commission to investigate, especially since Republicans in Congress just voted to bury Trump's tax returns from public scrutiny.
It isn't clear if Ross was the intermediary in this deal that netted Trump a $60 million profit on a garbage piece of real estate, but it had to be someone who knew Rybolovlev was going through a divorce and was looking to hide his assets in real estate trust and also knew that Trump needed an influx of cash to repay at debt to (surprise!) Deutsche Bank.
Now Ross is a cabinet secretary, so if any scandal about his ties to Russia come out, it will be a scandal inextricably tied to Trump.
You may also want to buy this week's New Yorker, which has a huge article on the dossier released earlier this year.