But Trump never dictated explicit details of the alleged quid pro quo, according to the public testimony given by Sondland Wednesday.
As NPR's Phil Ewing notes, Republican counsel Steve Castor asked Sondland, "Did the president ever tell you personally about any preconditions for anything?"
Sondland, simply responded, "No."
Expect Holmes to be pressed by lawmakers about an exchange he and Sondland had at the Kyiv restaurant once the phone conversation with Trump ended.
Holmes recalls the ambassador saying that Trump cares about "big stuff" that is beneficial to the president, like the "Biden investigation."
During the public hearing, Sondland said the only part of Holmes' testimony he takes exception to is that he himself never mentioned the Bidens by name.
He added he didn't know at the time of that the investigation into Burisma — the Ukrainian energy company on whose board former Vice President Joe Biden's son, Hunter, served for a time — was a code for the Biden family.
A history of taking a stand on issues
David Holmes joined the foreign service in 2002. He's served in a number of posts including in Kosovo, Kabul, New Delhi and Moscow, before his current post as counselor for political affairs at the U.S. Embassy in Ukraine.
In a tweet former U.S. Ambassador to Russia Michael McFaul said he had worked with Holmes, who "had the well-deserved reputation as a rising star in the State Department."
In 2014, Holmes won a "constructive dissent" award raising concerns about how the Obama administration was carrying out Afghanistan and Pakistan policy. Using the classified dissent channel, Homes sent a formal message where he explained the system at the time was cumbersome and that it "hindered our diplomatic effectiveness."
"His message was so good and so influential that it went all the way to the secretary of state," said Eric Rubin, and active duty foreign service officer and president of the American Foreign Service Association.
The William R. Rivkin award goes to mid-level officials at the State Department who shine a light on policy issues they observe.
Rubin, who also received the award in 1994, made clear it is not about whistleblowers, but rather recognizing someone who feels strongly enough to put themselves on record for voicing views on policy that may differ from the administration.
He said the memo Holmes crafted ultimately became "the subject of senior interagency meetings to discuss how to reorganize our approach to Afghanistan and Pakistan."
In an interview last week on All Things Considered, Dan Feldman, a former State Department official who worked with Holmes in Afghanistan and Pakistan, said Holmes represented "the best of the rising generation of foreign service officers."
"Many of the things that would signal that, he got even after he filed the dissent cable," Feldman said.
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