On March 24, 2017, Trenga was the first federal judge to rule in favor of the Trump administration's executive order that limits travel from six Muslim-majority countries.[6]

On May 16, 2019, Trenga re-incarcerated whistleblower Chelsea Manning, holding her in contempt after she refused to testify before a federal grand jury, adding the threat of daily fines up to $500 after 30 days and $1,000 after 60 days. This came a week after Manning was freed from 62 days of incarceration for the same offense before another federal grand jury.[7]

On September 4, 2019, Trenga ruled that the United States government's watchlist of “known or suspected terrorists” violates the constitutional rights of those listed on it.[8]

On September 24, 2019, Trenga set aside the conviction of Bijan Khan, business partner of Donald Trump's former National Security Advisor Michael Flynn, on acting as an agent for a foreign power without notifying the Justice Department. Flynn was found guilty and was awaiting sentencing in his own foreign power lobbying case.[9]

On March 12, 2020, Trenga rescinded his prior order imprisoning whistleblower Chelsea Manning, who had attempted to kill herself the day before.[10] Trenga ordered that Manning pay $256,000 in fines that had accumulated over the course of her confinement.[11]