From NBC News, this is a bonus episode of Article 2, Inside Impeachment.

I'm Steve Kurnaki.

Today is Tuesday, January 21st, and here's what's happening.

Do you solemnly swear that in all things appertaining to the trial of the impeachment of Donald

John Trump, President of the impeachment of Donald John Trump,

President of the United States, now pending,

you will do impartial justice according to the Constitution and laws,

so help you God.

I do.

Just after 1 PM Eastern time, the Senate impeachment trial began in earnest today.

Now we know there has been a lot happening today.

Maybe you've been watching it on TV, trying to follow it online, picking up bits and pieces where you can, but we wanted to take you through what I think is clearly the most significant development today.

And it started with a fight over the ground rules.

First, the Senate will hear an opening presentation from the House managers.

Second, we will hear from the President's Council.

Senate Majority Leader Mitch McConnell's proposed resolution which was released

late Monday night called for a shortened timeline that would not

automatically include the House's impeachment evidence.

Our straightforward resolution will bring the clarity and fairness that everyone deserves. This is the fair roadmap for our trial. We

need it in place before we can move forward. Under McConnell's rules, opening arguments would be confined to just 24 hours per side over only

two days.

Democrats responded with outrage.

...