House Intelligence Committee Chairman Adam Schiff refused to answer a question during President Trump’s impeachment trial about why he hired a former colleague of the alleged Ukraine whistleblower.

Sen. Ron Johnson, a Republican from Wisconsin, asked the opposing legal teams on Thursday why the California Democrat hired former National Security Council official Sean Misko, 37, the day after the July 25 phone call between Trump and Ukrainian President Volodymyr Zelensky that became an inciting incident for impeachment and what role he has played in the impeachment investigation.