Keeping along the lines of hearings, they will be numerous and voluminous over the next year at the commencement of the new House of Representatives. That a new checks and balances system is in place was imperative for a Senate and House which allowed Trump to run roughshod through potential ethics, emoluments, and criminal violations.

I'll expect a few folks (human and non-human) to be called to the table early and often.

The Interpreter
Ivanka
Eric
Kush
Kavanuagh
The tax returns.....

Along with some outside candidates with inside knowledge of the syndicate...

Bannon
Rudy
Ross
Pruitt

They may yield some results, they may waste time, they may be fruitless, but as long as they make Trump squirm, twist, gesticulate and gyrate into his daily Twitter/public madness, they'll be doing what they were elected to do.

Presenting facts and truth along with telling it is not a strong suit of this administration.