The president’s legal team has wrapped up its impeachment defense. What’s next? Senators will have two days to ask questions of each side. A crucial vote on whether to allow witnesses in the impeachment trial is expected Friday.

Pressure has been mounting on senators to call for witness testimony since passages from former national security adviser John Bolton’s forthcoming book were leaked to the press. In that book, Bolton alleges the president told him he wanted to withhold military aid from Ukraine until officials there launched an investigation into former Vice President Joe Biden and his son Hunter. Though the president denies he said this to Bolton, Trump’s former White House chief of staff, John Kelly, says he believes the apparent account.

We asked two people for their thoughts on the impeachment process so far:

Carolyn Shapiro clerked for Justice Stephen Breyer in 1996-1997. She’s associate professor at IIT Chicago-Kent College of Law, where she’s also the founder and co-director of the Institute on the Supreme Court of the United States.

Chris Bury is a senior journalist in residence at DePaul University and a special correspondent for the “PBS NewsHour.”

Below, a Q&A with our guests.

Chris Bury, you covered the Clinton impeachment as a correspondent for ABC’s “Nightline.” What are your thoughts on how this impeachment trial compares?

Biggest difference is Clinton admitted wrongdoing and apologized. He had gone on TV to apologize before the impeachment even started. Then the day he was acquitted he gave a heartfelt apology.

Another big difference was Clinton’s strategy to make it seem like business as usual at the White House during the impeachment trial. Trump, however, is consumed by it. Clinton was more disciplined in not talking about the impeachment proceedings.

Has Congress become more partisan since the Clinton impeachment?

Bury: I’d say the House was just as partisan back then, but the Senate is much more partisan than it was under Clinton.

Trump’s lawyer today called the leaked passages from John Bolton’s book “inadmissible.” Was he correct?

Shapiro: No, that’s ridiculous. Rules of evidence don’t apply in this Senate trial. Normally the reason it would be inadmissible is because it would be hearsay. It’s an argument that is using the technical words wrongly and out of context. It’s not an argument; it’s made up.

Chris, on Monday you tweeted: “For the record, Starr and the Clinton White House both leaked liked sieves to bias the impeachment narrative.” Tell us more.

Bury: Yes, both sides were trying to influence the narrative. Starr’s attorneys were leaking to the press. My ABC “Nightline” colleagues met regularly with Starr’s team to get information. And I met regularly with Clinton’s defense team.

Carolyn, how important is it for both sides to control the narrative?

Shapiro: Because this is a political process, the narrative matters enormously.

What do you think the next two days of questioning will look like?

Shapiro: Next two days will likely be as partisan as you can imagine. You’ll see a lot of senators trying hard to score points and make quotes that will get seen on TV and used in ads, but I don’t think we’ll learn anything substantive.