IE 11 is not supported. For an optimal experience visit our site on another browser.

A potential witness, Giuliani could still join Trump's defense team. It's happened before.

Analysis: Legal ethics rules for the courtroom address the issue of conflicts of interest.

President Donald Trump's defense team for his Senate impeachment trial will include, among others, White House counsel Pat Cipollone, his personal attorney Jay Sekulow, and Pam Bondi, the former Florida attorney general. Rudy Giuliani has reportedly wanted to be on the team, although there is no indication he will be added.

Indicted former Giuliani associate Lev Parnas implicated a lot of people by name in his explosive interview with Rachel Maddow last week.

Documents originating from Parnas include an email from Sekulow, revealing that he spoke to Trump about the president's former lawyer John Dowd representing both Parnas and his co-defendant, Igor Fruman. And Bondi joined the lobbying firm Ballard Partners in 2019. The firm's name appears in Parnas' recently released handwritten notes. Photos have also surface of Bondi with Parnas at social events.

Giuliani has long been suggested as a potential witness in an impeachment trial based on his activities in Ukraine, and he has already defied a congressional subpoena.

Some have pointed out that because these lawyers may have been involved in the conduct for which Trump has been impeached, they could be "conflicted out" of representing the president.

Of course, Trump's impeachment "trial," set to start on Tuesday, will be conducted differently than one in a courtroom. But under most rules of ethics, lawyers shall not try cases in which they are likely to be a necessary witness. Acting as both advocate and witness can prejudice the court and can also cause a conflict of interest. For example, if there is likely to be substantial conflict between the client's testimony and the lawyer's testimony, the representation presents a conflict of interest.

Determining whether there is a conflict is the responsibility of the lawyer, who must secure the client's informed consent in writing. There are some exceptions to the rule, including when disqualification of the lawyer would result in substantial hardship tn the client.

In the case of newcomer Bondi, there is less likely to be substantial hardship if she were disqualified because Trump hasn't had time to rely heavily on her. On the other hand, because attorneys Sekulow and Giuliani have been with Trump for a long time their disqualification could result in hardship to the president.

The D.C. Circuit Court of Appeals has held that disqualification of an attorney is a serious step, one which can severely affect the monetary interest and reputation of an attorney, and negate the client's right to freely choose his counsel. Any attempt to disqualify a lawyer faces an extraordinarily high burden: Disqualification is impermissible unless the attorney's conduct will tend to taint the trial and actually have the potential to affect its outcome.

Impeachment trials have featured lawyers as potential witnesses before.

Attorney Bruce Lindsey was part of President Bill Clinton's legal defense team in the Paula Jones and Monica Lewinsky cases.

Lindsey was subpoenaed by independent counsel (and now Trump impeachment defense lawyer) Kenneth Starr to testify before a grand jury convened for the Lewinsky matter. Lindsey refused to answer certain questions about conversations he had had with Clinton. The White House invoked executive privilege and attorney-client privilege, which caused a legal skirmish with Starr's team.

But Lindsey still served as part of Clinton's impeachment trial defense team in the Senate, despite being a potential fact witness.