Collusion with whom and in what would be criminal?

BooMan has answers.

And they make no reference to Russian efforts to manipulate public opinion by using bots or pseudonymous accounts to spread anti-Hillary propaganda, whether or not the Russians and the Trump campaign were in cahoots in that effort.

It's all about the hacks.

Let’s start with the essential point that hacking into the computer systems of the DNC and the DCCC are crimes. Using a phishing attack to steal John Podesta’s email password is a crime. 

Seeking to gain access stolen goods makes you an accessory to the crime and perhaps also a co-conspirator or conspirator after the fact. 

I’ll leave it to lawyers and prosecutors to define the exact statutes that might be implicated, but if what the Russians did was criminal, and it was, then what Trump’s team was doing was also criminal.

. . . .

And if you work with a foreign power that has hacked into your own nation’s government computers, that could violate additional statutes. 

If you offer things of value (like a relaxation in sanctions, for example) for stolen goods, that’s another crime.

. . . .

So, yes, there’s a big theory of the case that seeks to explain why Trump is so friendly with Vladimir Putin and eager to lift the sanctions on Russia.

. . . .

There’s a big collusion story and there’s a small one, too. 

The small one is already proven. 

Team Trump asked for stolen documents while knowing they were stolen. 

They made good faith offerings (a change in the Republican Party platform, for example) and dangled sanctions relief in order to entice the Russians to share illegally obtained dirt on Hillary Clinton. 

These are crimes. 

That’s collusion.