The first of President-elect Donald Trump’s most controversial nominees appeared Tuesday before the Senate Judiciary Committee, as civil rights advocates stepped up their attacks on Alabama Sen. Jeff Sessions, whose confirmation hearing for attorney general will likely serve as a contentious template for a close succession of Cabinet hopefuls to follow.

The 70-year-old former federal prosecutor and state attorney general has been quietly preparing for what promises to be a bruising daylong vetting to include questions about racial tolerance, a tough anti-immigration record and a return to harsh punishment for criminal offenders.

Yet even before he could take his seat at the witness table, protesters wearing Ku Klux Klan costumes erupted with shouts of "white power,'' before they were ushered out, the first clash of the day between demonstrators and Capitol police.

"If I am confirmed, we will systematically prosecute criminals who use guns in committing crimes,'' Sessions is expected to say, according to a copy of his opening statement. "We will prosecute those who repeatedly violate our borders. It will be my priority to confront these crises vigorously, effectively and immediately.''

Sessions, according to the written statement, also asserts a commitment to enforce civil rights laws, an issue on which he is expected to be aggressively challenged by Senate Democrats.

"I deeply understand the history of civil rights and horrendous impact that relentless and systemic discrimination and the denial of voting rights has had on our African-American brothers and sisters,'' Sessions is expected to say. "I have witnessed it...While humans must recognize the the limits of their abilities — and I do — I am ready for this job. We will do it right.''

Sessions spokeswoman Sarah Flores said the senator, a longtime member of the very committee that will consider his nomination, has participated in several mock hearings in recent days in anticipation of adversarial questioning from Senate Democrats who have signaled that they will offer little deference to their colleague.

"We've had a number of sessions varying in length that cover a large range of issues that could come before the attorney general,'' Flores said.

Though Sessions has spent two decades in the Senate and has participated in dozens of confirmation hearings as a committee member, supporters have emphasized the need for serious preparation if only to avoid a painful repeat of an appearance before the panel 30 years ago when he his nomination for a federal judgeship was was rejected, in part, for his racially charged comments.

Rep. John Lewis, D-Ga., an icon of the civil rights movement, and Sen. Cory Booker, D-N.J., have been added to the list of witnesses expected to oppose Sessions' nomination.

Invoking the name of the late Massachusetts Sen. Ted Kennedy, who during the 1986 judicial confirmation referred to Sessions as a "disgrace,'' Sen. Patrick Leahy, D-Vt., promised a close examination of a Senate colleague who worked against him on hate crime legislation and the reauthorization of the Violence Against Women Act.

"Sen. Sessions has repeatedly stood in the way of efforts to promote and protect Americans' civil rights,'' Leahy, a former chairman of the Judiciary Committee, wrote Monday. "He did so even as other members of the Republican Party sought to work across the aisle to advance the cause of living up to our nation's core values of equality and justice.''

California Sen. Dianne Feinstein, the panel's ranking Democrat, has called for a delay in the hearing, citing an accelerated schedule that has provided little time to review the nominee's record, including writings and speeches. The senior senator also has claimed that answers Sessions provided to the committee in a written questionnaire were incomplete.

Late last week, the Office of Government Ethics raised concerns about the rushed nature of the confirmation hearing schedule — six are scheduled Wednesday — that could compromise a full vetting of the nominees.

Senate Majority Leader Mitch McConnell of Kentucky has said the hearings are necessary to assemble Trump's incoming national security team, adding that Democrats' concerns about the schedule are "related to their frustration at having not only lost the White House, but having lost the Senate.''

Civil rights leaders opposed

A coalition of civil rights advocates, meanwhile, have stepped up their opposition in recent days, renewing a call for a hearing delay while characterizing the nominee as "unfit.''

Sherrilyn Ifill, president of the NAACP Legal Defense and Educational Fund, said Sessions' nomination was "particularly fraught.'' She specifically cited his failed prosecution of a 1985 voter fraud case in Alabama involving three local black activists that has become a cause célèbre for the senator's opponents.

The three were quickly acquitted, though the case has shadowed the senator since with questions about whether the then-federal prosecutor sought to intimidate black voters.

"What in the record of (Sessions') 40 years of service suggest that we can trust him to enforce the nation's civil rights laws?'' Ifill told reporters.

Albert Turner Jr., the son of two of the activists charged in the case, issued a surprise endorsement of Sessions' last week, dismissing claims that the prosecutor's actions then were motivated by race.

"My differences in policy and ideology with him do not translate to personal malice,'' Turner said. "He is not a racist. ... He was presented with evidence by a local district attorney that he relied on, and his office presented the case. That’s what a prosecutor does. I believe him when he says that he was simply doing his job.''

Turner's elderly mother, Evelyn Turner, however, said the matter remained a painful chapter in the family's life and would not support Sessions' nomination.

High-profile supporters

Still, Sessions' team has assembled a stable of high-profile supporters. Among them: former attorney general Michael Mukasey, former deputy attorney general Larry Thompson and former FBI director Louis Freeh.

Mukasey and Thompson are set to testify on Sessions' behalf before the committee Wednesday.

On Tuesday, though, it will be up to Sessions himself to defend a long public record and his nomination for the job as the nation's chief law enforcement officer.

In a prepared opening statement, Sessions is expected to outline his priorities for the sprawling Justice Department. It is an agenda, Flores said, will address the "threats that rising crime and addiction rates pose to the health and safety of our country; protecting our citizens against the scourge of radical Islamic terrorism; and respecting the men and women in law enforcement across the country.''

"Our hearing today hardly introduces Sen.Sessions to the committee,'' Iowa Sen. Charles Grassley, the panel's Republican chairman said in remarks prepared for delivery Tuesday. "No, we’re here today to review the character and qualifications of a colleague who has served alongside us in the Senate for 20 years.

"And every member of this committee knows from experience that, in his new role, Sen. Session will be a leader for law and order without regard to person.''