WATCH: Demonstrators shout 'Lock him up!' as Paul Manafort heads to court

On Friday, as President Donald Trump gave a bizarre, rollicking press conference on the White House lawn, former Trump campaign adviser Paul Manafort made his way to federal court in New York City.

Manafort faces charges of witness tampering.

Special counsel Robert Mueller claims Manafort reached out to potential witnesses, violating the terms of his bail. Currently under house arrest, Manafort might end up in jail today if the federal judge sides with prosecutors. The threat of a lengthy incarceration might sway Manafort to share more information with Mueller's team.

As Manafort walked to court, a crowd of demonstrators shouted "Lock him up."

Watch: