Ousted ambassador to testify in Trump impeachment probe

The House will hear from a singular witness Friday in the Trump impeachment hearings: Marie Yovanovitch, the former U.S. ambassador to Ukraine who was targeted by the president's allies in a smear campaign now central to the inquiry.

The career diplomat, who served both Republican and Democratic presidents, is expected to relay her striking story of being suddenly recalled by Donald Trump and told to watch my back in a swiftly developing series of events that sounded alarms about the White House's shadow foreign policy.

She and other officials now testifying publicly in the historic House hearings scrambled to understand Trump's actions, providing revelatory accounts that Democrats are now relying on to make the case that the president's behavior is impeachable.

In particular, Yovanovitch and others have described Rudy Giuliani, Trump's personal lawyer, as leading what one called an irregular channel outside the diplomatic mainstream of U.S.-Ukraine relations.

Asked during her closed-door deposition if anyone at the State Department who was alerted to Giuliani's role tried to stop him, she testified,