The Rev. William J. Barber II, a pastor and activist who has emerged as a leading religious critic of President-elect Donald Trump, was just off a red-eye flight from California on Monday morning when he arrived on Capitol Hill. Slowed by spinal arthritis and leaning on a cane, he crossed a sidewalk to an outdoor lectern in front of a church, where hundreds of protesters had assembled.

If the traveler was weary, his deep voice betrayed no hint of it.

“Today we face a moral crisis,” said Barber, the top official of North Carolina’s NAACP and president and senior lecturer of an interfaith, interracial activist group called Repairers of the Breach. “A misguided ruler, Trump, has nominated Senator Jeff Sessions for attorney general of the United States. But Sessions’s immoral record shows consistent support for ideological extremism, racist and classist policies, and the writing of discrimination into laws.”

Barber, who delivered a well-received speech to the Democratic National Convention in July, advocating social justice with a thundering, evangelical passion, was visiting Washington in advance of Tuesday’s scheduled Senate confirmation hearing for Sessions (R-Ala.).

With several clergy members of various faiths, he led about 500 demonstrators on the short march from the Lutheran Church of the Reformation to the Russell Senate Office Building, where they filed in ranks of two along the marble hallways, reciting their grievances against Sessions, and delivered an anti-Sessions petition to the offices of Senate Majority Leader Mitch McConnell (R-Ky.) and others.

“Just because somebody’s nice doesn’t mean they’re not racist,” Barber told the gathering at the church, before they set out for the Russell Building, inching along East Capitol Street NE in the frigid air. This apparently was a reference to Sessions’s personal popularity in the Senate, where he has a reputation for being collegial, patient and attentive toward political allies and foes.

“No, you don’t have to be loud and overt to be racist,” the pastor said, his voice rising. “We’re talking about systemic racism. You have to look at policies. How people voted. Not whether they follow parliamentary procedures. What was the impact of the policy?”

Since joining the Senate in 1997, Sessions has stood against almost every immigration bill that included a path to citizenship for people residing in the United States illegally. He also voted against renewing the federal Violence Against Women Act, has supported a constitutional ban on same-sex marriage and opposed the Matthew Shepard and James Byrd Jr. Hate Crimes Prevention Act.

In 1986, after being nominated for a federal judgeship, he was rejected by the Senate because of allegations that he had improperly prosecuted black voting-rights activists and had used racially offensive language as a U.S. attorney in Alabama. More recently, he publicly supported a Supreme Court decision that killed key provisions of the Voting Rights Act of 1965 that had protected ballot access for African Americans.

After he became one of Trump’s earliest supporters in Congress, endorsing the billionaire businessman’s Republican candidacy in February, Sessions played a role in nearly every major policy decision by Trump, who has called for restrictions on Muslim immigration into United States.

At Monday’s pre-march rally, clergy members were vehement in denouncing Sessions.

“We will not return to an era of hatred that we have … worked tirelessly already to eradicate,” said the Rev. Jennifer Butler, chairwoman of President Obama’s Advisory Council on Faith-based and Neighborhood Partnerships.

“The role of the attorney general requires a demonstrated commitment to providing equal protection under the law,” Rabbi Jason Kimelman-Block, director of Bend the Arc Jewish Action, told the crowd. “Jeff Sessions unequivocally fails that test.”

Imam Ali Siddiqui, who leads worship services at different mosques in the Washington area, stood at the lectern. “Resist, resist, resist,” Siddiqui implored the protesters, calling Sessions “evil incarnate.”

Barber, who has been fighting Republican officials in North Carolina for months on issues involving voting rights and social spending, is one of the main organizers of “Moral Mondays” — weekly rallies by progressive activists of all stripes in the Tar Heel state. The demonstrations were fairly small in the beginning, attracting a few dozen protesters, but the crowds have since grown into the thousands.

After excoriating Sessions outside the church Monday, he turned his attention to fellow evangelical Christians.

“Donald Trump and Jeff Sessions have backing from groups that like to call themselves white evangelicals,” he said. “Well, I know a lot of white evangelicals. … Those who have chosen to get behind the race-driven, class-driven agenda of Trump and his pick — namely, white evangelicals — are engaging in theological malpractice and heresy. … It is a form of heresy to attempt to use faith to endorse hate and discrimination and injustice.”

Later, as he walked from office to office in the Russell Building, chatting with a reporter, Barber, 53, said that he had been in San Francisco before jetting overnight to Washington.

“I was meeting with lawyers,” he said, leaning against an elevator wall, sighing restfully for the first time. “I’m trying to get them to come to the South and help us. Like Joan Baez brought her music to the South. I told them, ‘We need you to come to the South and help us fight.’ ”

He said: “April to November, I traveled this country, went to 22 different states. I saw thousands of people turn out for our moral revival. … I think what we’re facing in our opposition — it’s like what they used to say in South Africa: A dying mule kicks hardest. These extremists keep cheating, on voting rights, on gerrymandering, on all sorts of issues, and I think the reason they’re cheating is they know they’re losing.”