(CNN) A leading Christian magazine founded by late evangelist Billy Graham -- father of key presidential supporter Franklin Graham -- published an op-ed on Thursday calling for President Donald Trump to be removed from office and urging evangelicals not to support him.

"Whether Mr. Trump should be removed from office by the Senate or by popular vote next election—that is a matter of prudential judgment," Christianity Today's editor in chief, Mark Galli, wrote in the op-ed . "That he should be removed, we believe, is not a matter of partisan loyalties but loyalty to the Creator of the Ten Commandments."

Galli, who told CNN's John Berman on Friday he is leaving the publication, continued, "We believe the impeachment hearings have made it absolutely clear, in a way the Mueller investigation did not, that President Trump has abused his authority for personal gain and betrayed his constitutional oath. The impeachment hearings have illuminated the president's moral deficiencies for all to see."

"None of the president's positives can balance the moral and political danger we face under a leader of such grossly immoral character," he added.

The publication, an influential one among evangelicals, has criticized Trump before on immigration and other issues, but never before called for his removal. The op-ed shows potential reasoning for dissent among a key faction of the Republican coalition as Trump prepares for a potential Senate trial following his impeachment by the House of Representatives Wednesday night.

"To the many evangelicals who continue to support Mr. Trump in spite of his blackened moral record, we might say this: Remember who you are and whom you serve," Galli wrote. "Consider how your justification of Mr. Trump influences your witness to your Lord and Savior. Consider what an unbelieving world will say if you continue to brush off Mr. Trump's immoral words and behavior in the cause of political expediency."

Trump dismissed the criticism on Friday morning, calling the publication a "far left magazine" and drawing a contrast between himself and the Democrats seeking the 2020 presidential nomination.

"No President has done more for the Evangelical community, and it's not even close. You'll not get anything from those Dems on stage," he tweeted.

A far left magazine, or very "progressive," as some would call it, which has been doing poorly and hasn't been involved with the Billy Graham family for many years, Christianity Today, knows nothing about reading a perfect transcript of a routine phone call and would rather..... — Donald J. Trump (@realDonaldTrump) December 20, 2019

Speaking to Berman on CNN's "New Day" Friday, Galli said Trump's characterization of his magazine as "far left" is "far from accurate."

"We consider ourselves and most people consider us a pretty centrist magazine in the evangelical world. ... We rarely comment on politics unless we feel it rises to the level of some national or concern that is really important. And this would be a case."

The magazine's web servers were strained by all the web traffic when the editorial came out on Thursday afternoon. After some temporary hiccups, service was mostly restored.

Jim Wallis, one of the nation's most prominent liberal evangelical leaders, called the op-ed's stance a "huge, watershed event," adding that the magazine is arguably the leading evangelical magazine in the nation.

"What CT is saying in their editorial is removing Donald Trump from office is now a matter of faith, not politics, and I agree," Wallis told CNN.

Wallis, founder of Sojourners magazine, says evangelicals made a "Faustian" bargain with Trump -- appoint the federal judges we want and we will look the other way.

"They have made the Faustian bargain that no matter what he does, it's all acceptable because he gives them the judges he wants," says Wallis, author of "Christ in Crisis: Why We Need to Reclaim Jesus."

As far as the impact of the announcement, Wallis says it may impact two groups of evangelicals the most: suburban white women and younger evangelicals who are already jaded by older evangelicals' embrace of Trump.

"I bet there are going to be a lot of younger evangelicals who are going to be really excited," Wallis said about the editorial.

He says there are now cracks in the wall of evangelical support for Trump. The call for removal may not sway the majority of evangelicals but just enough to make a difference in the 2020 election.

"You don't need a whole lot to shift the race, just a few votes in key places in key states could make the ultimate difference" Wallis said.

But Franklin Graham tweeted early Friday morning that his father would "not agree" with Christianity Today's op-ed, adding that his father voted for Trump in 2016.