The Senate confirmation hearing for Jeff Sessions, Donald Trump's nominee for Attorney General, was interrupted by protesters dressed as the Ku Klux Klan in a demonstration against his apparent civil liberties stance.
Civil liberties advocates have expressed concern over the Alabama politician's voting record and his appearances before groups that espouse harsh views on Muslims and immigrants.
He was rejected for a federal judgeship by the Senate Judiciary Committee 30 years ago amid accusations that he made racist remarks.
As security escorted the protesters out of the room, they shouted: "You can't arrest me, I am white!" and "white people own this government!".
One protester told reporters: "What I am saying to Jefferson Beauregard [Session's full first names], that he is a racist. Senator Sessions is a racist and he only continues racist policies."
Meanwhile, police arrested approximately 10 people who conducted a sit-down protest in the Senator's office calling on him to withdraw his nomination.
Chanting "one person, one vote" and "stop Sessions", the demonstrators were led away peacefully by police.
At the hearing, Sessions denies allegations of racial animosity and called such claims part of 'false' caricature.
In a prepared opening statement, Sessions said he understands "the history of civil rights and the horrendous impact that relentless and systemic discrimination and the denial of voting rights has had on our African-American brothers and sisters."
"The office of the attorney general of the United States is not a political position, and anyone who holds it must have total fidelity to the laws and the Constitution of the United States," he added.
He vowed to improve relationships between police and minority communities if selected as Attorney General and disavowed the KKK and its "hateful ideology".
He also said he intends to protect the rights of gay, lesbian and transgender people.
Sessions cast himself as a strong protector of law and order promising that he would crack down on illegal immigration, gun violence and the "scourge of radical Islamic terrorism".
Sessions, who has served 20 years in the Senate, is known as one of the most conservative members of the upper chamber with strong stance on immigration.
He was accused of calling a black assistant US attorney "boy" and telling him to be careful about how he spoke to "white folks" but he denied making the comments.
He did admit saying the National Association for the Advancement of Colored People (NAACP) was "communist-inspired".
Sessions also promised to "recuse himself" from any investigation there might be into Democrat Hillary Clinton, because of comments he'd made during the campaign.
Trump said previously that he would name a special prosecutor to look into Clinton's use of a private email server, but has since backed away.
The FBI and Justice Department declined to bring charges last year.
Opening the two-day hearing, Senate Judiciary Chairman Charles Grassley described Sessions as "a man of honour and integrity, dedicated to the faithful and fair enforcement of the law".
Sessions has solid support from the Senate's Republican majority, but faces a challenge persuading sceptical Democrats.
Senator Dianne Feinstein hinted at those concerns, saying "there is so much fear in this country" particularly among blacks.
Asked by Grassley if he could stand up to Trump if he disagreed with his actions, Sessions said yes, adding that he would be prepared to resign if asked to do something "plainly unlawful".
Democrat Senator Cory Booker, one of three black senators, said he will testify against Sessions on Wednesday in what his office called an unprecedented instance.
He accused Sessions of having a "concerning" record on civil rights and criminal justice reform and called his decision "a call to conscience."
If confirmed, four-term senator Sessions would succeed Attorney General Loretta Lynch and would be in a position to reshape Justice Department priorities in the areas of civil rights, environmental enforcement and criminal justice.