President Trump relishes his reputation as a savvy dealmaker. “Deals are my art form,” he once tweeted. “Other people paint beautifully or write poetry. I like making deals, preferably big deals.” He promised during the 2016 campaign that if elected, he would work with politicians and foreign leaders to make “smart deals for the country.” But since he took office there has been precious little evidence of Trump’s vaunted dealmaking prowess. Such successes as his administration has been able to claim have generally been accomplished without his direct involvement—and sometimes in spite of it.

There is, though, one obvious piece of evidence from the president’s political career that suggests his dealmaking reputation might be deserved after all: the relationship he has with evangelical political leaders. He has lavished them with attention and let them bask in his celebrity star-power, things that they, long feeling like outsiders in American culture and politics, have badly craved. In exchange, they have thrown him their support—unconditional support, by all appearances—and with it, the backing of a political constituency vital to his success at the polls.

In The Faith of Donald J. Trump, authors David Brody and Scott Lamb provide an in-depth look at the relationship between the president and American evangelicals. Brody and Lamb—respectively a newscaster with Pat Robertson’s Christian Broadcasting Network and a vice president at Jerry Falwell’s Liberty University—have written what they dub a “spiritual biography,” even though they come right out and say they have no intention of answering the question of whether Trump is a Christian. Instead, they hope to convey his faith through his actions.