The Rev. Franklin Graham says a potential 2024 presidential bid by Donald Trump would "be a very tough thing to do," the prominent Christian leader told "Axios on HBO."

Why it matters: Graham, the president of the Billy Graham Evangelistic Association and Samaritan's Purse, was among Trump's earliest and most prominent evangelical defenders.

Graham told "Axios on HBO" that a Trump comeback would be difficult because of his advancing age and eating habits.

• "“I think for him, everything will depend on his health at that time. If he still has energy and strength like he does. I don't."
• "You know the guy does not eat well, you know, and it's amazing the energy that he has."
• "He's lost weight, fifteen pounds, Maybe. So he might be in good health and in good shape. I don't know."

Trump would be 78 in 2024, the same age as Joe Biden in 2020.

The big picture: Graham stood by Trump through repeated scandals, telling "Axios on HBO" in 2018 that he saw Trump as a defender of the faith.

• "Now people say 'Well Frank but how can you defend him, when he's lived such a sordid life?' I never said he was the best example of the Christian faith. He defends the faith. And I appreciate that very much."