Pope Francis will wash the feet of 12 inmates at Rome's central prison on Thursday for a ritual that dates back to his first Holy Week as pope five years ago. It led to backlash because women and Muslims were included, one of several actions that have raised concerns among conservative Catholics.

Dozens of theologians, priests and academics have also accused the pope of spreading heresy with his 2016 document called "The Joy of Love." Critics panned his opinions on marriage, moral life and the sacraments.

"He's the most powerful man in the church. He's an absolute monarch in certain ways, and yet his powers are supposed to be tightly circumscribed because he's not supposed to change essential things that his predecessors have taught going all the way back 2,000 years," said New York Times columnist Ross Douthat. He delves into the controversy and its impact in his new book, "To Change the Church: Pope Francis and the future of Catholicism," published by Simon & Schuster, a division of CBS.

"So a lot of the drama of the Francis pontificate… bishops and theologians arguing with each other, cardinals challenging the pope and so on, reflects what happens, this fascinating thing, when a pope sets out to push the limits of his office," Douthat said.

In his book, Douthat, a Catholic himself, compares Rome under Pope Francis to that of Washington, D.C., under President Trump: "a paranoid jumpy place, full of ferment and uncertainty."

"I want to be clear. I'm not drawing any kind of moral comparison between the Holy Father and President Trump. The comparison is more of their role within their respective institutions. Both of them have entered institutions, the U.S. government and the church of Rome, that have major credibility problems that are sort of creaking and straining under the pressures of modernity," Douthat said.

While they are different figures, Douthat said he thinks they both "speak to this moment in the West generally where there's this sense that all of our institutions, governmental, religious and so on, aren't working particularly well."

"So there are openings for populists, for reformers. The question is just whether those reforms actually deliver what they're trying to promise," Douthat said.