Melber interviewed former Trump campaign manager Corey Lewandowski in Feb. 2019 about whether Trump asked him to interfere in the Mueller probe, and Melber later reported that Lewandowski's response was false. In a congressional impeachment hearing in Sept. 2019, Lewandowski was questioned about his false answer.
On the night of the 2018 midterm elections, Melber broke a story live on MSNBC that Democrats on the Ways and Means Committee "intend to request President Trump's tax returns." In April 2019, United States House Committee on Ways and Means Chairman Richard Neal carried out that plan, formally requesting Trump's tax returns from the IRS.
Melber has drawn attention for his interviewing and questioning skills. He was nominated for an Emmy Award for "Outstanding Live Interview" for interviewing four key witnesses in the Mueller probe at once. In November 2019, Columbia Journalism Review stated Melber is "a remarkably effective interviewer", adding "his veins appear to contain ice water; he betrays no emotion at all" during intense exchanges. The New York Times columnist Peter Wehner, a former White House official in GOP administrations, said in February 2019, "Melber is an outstanding interviewer, among the best on television."