White House physician Ronny L. Jackson speaks to reporters during the daily briefing on Jan. 16. (Jabin Botsford/The Washington Post)

The seemingly never-ending parade of staff changes in the Trump administration continued apace Wednesday, with the president announcing that Veterans Affairs Secretary David Shulkin is out and that White House physician Ronny L. Jackson will replace him.

Jackson's name will be familiar to political watchers across the country for one main reason: He's the physician who delivered what some felt to be a suspiciously rosy picture of Trump's health in January. But he's an interesting pick for a whole host of other reasons.

For one, Jackson is something of a nonpartisan pick. Like Shulkin, he served in the Obama administration, where he was also President Barack Obama's White House physician. A native of Texas and a graduate of Texas A&M and University of Texas Medical Branch, he's a rear admiral in the U.S. Navy who has spent decades practicing medicine in the military. Jackson was nominated for a promotion to rear admiral (upper half) as recently as last week, which would give him his second star. According to his Navy biography, he was deployed to Iraq in the mid 2000s to head up an emergency medical unit tasked with resuscitating troops.

While there, he was chosen to join President George W. Bush's White House as a physician. In 2013, Obama promoted him to the top job in the West Wing. Trump elected to keep him on. In that role, Jackson oversees not just Trump's health, but also that of the first family and White House staff and guests. He mostly stayed behind the scenes but made headlines after treating a girl who got bit by one of the Obamas' dogs in January 2017.

Jackson reached his highest degree of notoriety in January, when he delivered a promised review of Trump's health. Trump, who at 70 was the oldest newly elected president ever, is known to eschew exercise and dine on fast food. There have also been persistent questions — especially among his critics — about his mental health. And Trump's medical reviews during the campaign were both ridiculously hyperbolic — claiming he would be the most healthy president ever — and omitted key pieces of information, including a hair-loss drug Trump takes.

Jackson's review played up a cognitive test Trump had passed that seeks out early signs of dementia and other kinds of mental deterioration. He said Trump had “incredible genes” and (seemingly) joked that if Trump's diet had been better he might live to be 200 years old. He denied Trump had heart disease even as the data suggested he might. He listed Trump's weight at 239 pounds, which left Trump exactly one pound shy of the definition of “obese” and spawned a whole host of dubious reactions. (Call it the “girther” movement.)

The whole thing earned Jackson a send-up during the cold open of “Saturday Night Live.”

Despite the ridicule, members of the Obama administration vigorously defended Jackson as a patriot and an honest man.

If nothing else, Jackson's ascension seems to reinforce that the best way to get ahead in the Trump administration is to say nice things about him. Some defended Jackson's credentials, but that review will likely be a topic at his confirmation hearings.

Perhaps the main reason Jackson is a somewhat controversial pick, though, is his lack of management experience. VA has been a department beset by scandals in recent years — including before Shulkin — and has proved a logistical and bureaucratic nightmare. Jackson has headed up medical units in the White House and Iraq, but he has never dealt with anything close to the scale of what he's set to take on. It may be the toughest Cabinet job in the entire administration, in fact.

Trump, though, as he often does, has gone with a nontraditional pick who said things he liked on television.