After evangelical publication Christianity Today published a blistering editorial on what it called U.S. President Donald Trump's "grossly immoral character," some church leaders and the president himself denounced the criticism as elitist and out of touch.

The Dec. 19 editorial sparked a Christmas holiday debate over religion in U.S. politics, and posed new questions about the close alignment between white evangelical voters and Trump, who has given their beliefs strong political support.

However, the coziness with the Republican president, who was impeached this month by the Democrat-controlled House of Representatives, is exacerbating a long-term crisis facing white evangelicalism, some Christians say — it is being abandoned by younger generations.