Washington (CNN) Protesters clashed outside the offices of key swing vote lawmakers after the Senate voted Friday to advance Brett Kavanaugh's Supreme Court nomination.

Demonstrations have swamped Capitol Hill throughout the Kavanaugh confirmation process.

Key undecided senators -- as well as congressional leaders -- have been receiving the majority of the protests, in particular key remaining undecided senators Republican Susan Collins of Maine and Democrat Joe Manchin of West Virginia.

The protests have been a consistent reminder of the political pressures lawmakers face and have been a constant occurrence along side Kavanaugh's nomination, which has been rocked by an allegation of sexual assault and accusations of inappropriate sexual behavior. Kavanaugh has denied all allegations against him.

According to a Capitol Hill police officer, authorities are investigating a female protester allegedly assaulting a man outside Collins' office, and two people have been detained and are currently being questioned. Police do not know the extent of the alleged assault, according to the officer.