U.S. Sen. Doug Jones of Alabama posted a video on Twitter today after the opening statements by President Trump’s lawyers in the impeachment trial, saying the Senate needs testimony from key witnesses to fully understand the case.

The president’s lawyers characterized the impeachment charges as an effort by Democrats to overturn the the 2016 election, a political crusade rather than a fact-driven investigation. They gave two hours of arguments today and will resume on Monday. Their arguments followed three days of arguments from Democrats, who wrapped up on Friday.

Jones, a Democrat, said he believes the House managers made a strong case on both articles of impeachment. He said he is concerned that the House didn’t press harder to subpoena key witnesses, but said it’s not too late to hear from them.

“We need the complete truth,” Jones said. “This is not just a question in my view of the president’s lawyers poking a hole in a case. It is about giving the American public the truth about what happened with the withholding of the aid and on the White House meeting. What happened? Where are those witnesses?”

Jones said the Senate needs to hear from former national security adviser John Bolton and acting White House chief of staff Mick Mulvaney, among others.

Jones had previously said it was important to hear testimony from Bolton.

“If the president of the United States really wants the American people to know the truth behind all this, let ‘em go. Let your people go and testify.”