BIRMINGHAM, Ala. — A leading figure among religious liberals says the candidacy of Roy Moore for US Senate is a struggle for the ‘‘soul of the nation.’’

The remarks on Saturday by the Rev. William J. Barber come a day after a letter signed by dozens of progressive pastors in Alabama said Moore — dogged by recent allegations of inappropriate conduct toward teenage girls decades ago — is unfit to serve.

Barber, former head of the North Carolina NAACP, spoke at an anti-Moore rally at the Tabernacle Baptist Church in Birmingham that drew more than 100 people.

The event was in direct contrast to a news conference Thursday during which religious conservatives expressed their commitment to Moore, who describes himself as a conservative Christian who hews to family values.

Signs carried by Moore opponents at Saturday’s rally decried his opposition to gay and transgender rights. Moore was also criticized for opposing federally backed health care, assistance for the needy, and more.

Barber and other speakers claimed Moore’s campaign is fueled by a perversion of Christianity linked with white supremacy, and Moore is trying to take those forces to the Senate.

‘‘What is happening now in Alabama matters for the soul of the nation,’’ said Barber, of Goldsboro, N.C., and the force behind the ‘‘Moral Monday’’ protest movement that calls for greater rights for gays and minorities.

By Friday, more than 50 Alabama pastors had signed a public letter stating Moore isn’t fit to serve in the US Senate. The letter continued to collect signatures Saturday.

The letter says Moore demonstrated ‘‘extremist values’’ incompatible with traditional Christianity even before recent allegations of sexual misconduct involving young women.

The pastors cite Moore’s opposition to the expansion of Medicaid, which provides health care for the poor. It also accuses him of denigrating people from other countries and faiths and cites his opposition to homosexuality.

The letter was written by a group of pastors in Birmingham. It includes the signatures of ministers from mainstream and liberal denominations including Methodists, Presbyterians, Episcopalians, the United Church of Christ, and some moderate Baptists.

Moore still enjoys the support of conservative evangelical leaders, but he has ignored mounting calls from Washington Republicans concerned that if he stays in the race he may not only lose a seat they were sure to win but also may do significant damage to the party’s brand among women nationwide as the party prepares for a difficult midterm election season.

Since last week, Moore has been engulfed by accusations of sexual misconduct toward women in their teens when he was a deputy district attorney in his 30s. Several of his accusers have allowed their identities to be made public.

One said Moore molested her when she was 14. Another said Moore assaulted her when she was a 16-year-old waitress after he offered to drive her home. Five others said Moore pursued romantic relationships with them when they were between the ages of 16 and 18.

President Trump has also been mostly silent on the accusations facing Moore, saying they are troubling but stopping short of calling for his withdrawal from the race, as other top Republicans have done.

Trump’s response have been notably different for some Democrats facing misconduct allegations.

On Thursday night, the president tweeted about Senator Al Franken of Minnesota saying that a photograph of Franken appearing to grope a woman ‘‘is really bad, speaks a thousand words’’ and chastising the Minnesotan for ‘‘lecturing anyone who would listen about sexual harassment and respect for women.’’

Trump has also said he was not surprised by accusations against film producer Harvey Weinstein, a major Democratic donor.; released an ad during the presidential campaign calling former New York representative Anthony Weiner a ‘‘pervert’’; and hosted a campaign news conference with three women who had accused former president Bill Clinton of sexual assault or misconduct, calling those women ‘‘very courageous.’’

White House press secretary Sarah Sanders on Friday pushed back against the idea that Trump treats Democrats differently than Republicans, pointing to comments of concern over the Moore allegations. Sanders also said that there was a key difference between the accusations against Franken and those against Trump.

‘‘Senator Franken has admitted wrongdoing, and the president hasn't,’’ Sanders said. ‘‘I think that’s a very clear distinction.’’