JUDY WOODRUFF:

Now back to the swirl of news surrounding the White House, the FBI's Russia probe, and more, with the analysis of Shields and brooks. That's syndicated columnist Mark Shields and New York Times columnist David Brooks.

Welcome, gentlemen. So much to talk about. What a week. I don't even know where to begin.

I will mention that CNN has just been reporting in the last few minutes that they have from several sources that White House lawyers are beginning to at least research the mechanism of impeachment. They don't have reason to believe, the story says, that anything like that is going to happen soon, but they are looking into it.

But, David, this week, again, there is so much to talk about, but let's talk about the appointment of a special counsel, Robert Mueller, the former FBI director, in the midst of this, all this speculation about the Russia connection. What does this do to the cloud hanging over the White House?