Lawmakers on both sides of the aisle are cautious: there are no articles of impeachment and the House hasn't voted to impeach the President. But, the logistical undertaking of a Senate impeachment trial isn't an easy lift and can't snap into action overnight leading to conversations that have begun in even small ways.

Talks are underway between Senate aides and even Supreme Court Chief Justice John Roberts' team over simple things like where Roberts' office will be during the trial, one Senate aide told CNN. The last time the Senate did this was the 1990s for the trial of then-President Bill Clinton, when staffers didn't all need their own computers and the chief justice was housed just off the Senate floor in the Senate president's room.

That room, logistically speaking 20 years later, isn't likely to work in an era where staffers need hardwired internet. Senate Majority Leader Mitch McConnell, Republican of Kentucky, has been preparing members for the reality of what is to come: six-day work weeks, no talking on the Senate floor and the reality that not much Senate business -- if any -- will get done.

And, behind the scenes, some members and aides have been brushing up on the Federalist Papers and re-watching the Clinton impeachment, trying to gear up for what is an incredibly complicated and unusual process.

Read More