Evangelical Christians have been one of Donald Trump’s most unwavering bases of supporters, but a new poll shows there may be cracks in this critical group.

A new poll from Politico/Morning Consult showed that 43 percent of evangelical voters would support Trump being removed from office as the impeachment process moves to the U.S. Senate. The House this week passed two articles of impeachment against Trump related to his alleged attempts to pressure Ukraine into digging up dirt on political rival Joe Biden, and Trump is expected to face a Senate trial in 2020.

The poll found that 51 percent of registered voters in general support Trump being removed from office, including 42 percent who said they strongly approve of his removal. The poll found that 42 percent opposed Trump being removed from office, including 38 percent who strongly opposed.

But the high number of evangelical voters supporting Trump’s removal could be a bad sign for Trump if he does win acquittal from the Senate, as is expected given the body’s Republican majority. These voters have been one of the most reliable groups of support for Trump, with numbers that rival Republican voters. An NPR/PBS NewsHour/Marist poll, released in July found that 73 percent of white evangelical Christians approved of the job Trump is doing in the White House, while only 23 percent disapproved.

But Trump came under intense scrutiny this week from one of the most influential evangelical publications, the magazine Christianity Today. In a piece published after Trump was impeached, editor-in-chief Mark Galli wrote that Trump must be removed from office for abusing the office of the presidency in an act that he wrote was “profoundly immoral.”

Trump responded by attacking the publication as a “far-left” and “progressive” publication, prompting Galli to push back.

“We consider ourselves and most people consider us a pretty centrist magazine in the evangelical world. It’s factually inaccurate we’re far left,” he said during an appearance on CNN.

“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.”

While it appears unlikely that Trump will be removed from office, especially considering that Senate Majority Leader Mitch McConnell has said that he plans to work in unison with the White House during the Senate trial and will be working for Trump’s acquittal, losing the support of even a portion of evangelical voters would make winning re-election in 2020 a much steeper climb.