Washington (CNN) When President Donald Trump named White House physician Ronny Jackson as his choice to be the next head of the Department of Veterans Affairs, it caught lots of people -- inside and outside 1600 Pennsylvania Avenue -- by surprise.

After all, Jackson had never run an agency even close to the size of the VA. And, it appeared that Jackson's main appeal to Trump was their personal rapport -- as well as the clean bill of health Jackson had given Trump after his annual physical. (Jackson's performance at a news conference announcing the results of that physical didn't hurt either.)

"He's like central casting -- like a Hollywood star," Trump said of Jackson in a speech to donors at his Mar-a-Lago resort in February.

"Republicans and Democrats on the Senate Veterans Affairs Committee are raising concerns about allegations involving Rear Adm. Ronny Jackson, President Donald Trump's nominee to lead the Department of Veterans Affairs, and are reviewing them to determine if they are substantial enough to upend his nomination.

"Committee members have been told about allegations related to improper conduct in various stages of his career, two sources said."

The White House, according to CNN reporting, has no plans to pull Jackson's nomination.

"Admiral Jackson has been on the front lines of deadly combat and saved the lives of many others in service to this country," said White House deputy press secretary Hogan Gidley on Tuesday morning. "He's served as the physician to three Presidents—Republican and Democrat—and been praised by them all. Admiral Jackson's record of strong, decisive leadership is exactly what's needed at the VA to ensure our veterans receive the benefits they deserve."

But, Jackson's confirmation hearing -- originally set for Wednesday -- was postponed Tuesday amid the allegations.

This is what happens when you govern by personal preference and favor seat-of-the-pants decisions rather than more thought-out ones.

Trump has made no secret of his unwavering belief in the rightness of his gut. He is an instinctual actor; he goes with what feels right as opposed to what conventional wisdom or the graybeards of Washington tell him is right.

It worked like a charm during the 2016 campaign. Trump went from an asterisk to the White House by -- and I am only oversimplifying slightly here -- doing the opposite of what everyone said he should. ( Thank you George Costanza !)

When he won, Trump tried to do what he thought conventional wisdom said he should. He tried to make nice with the Washington establishment by hiring former Republican National Committee Chairman Reince Priebus as his chief of staff. He trusted House Speaker Paul Ryan and Senate Majority Leader Mitch McConnell when they laid out an ambitious schedule to get rid of Obamacare and replace it with a conservative alternative.

But almost none of that worked. Trump chafed at being managed. Health care legislation stalled. Trump's poll numbers flagged. The momentum he had built coming off the biggest upset in modern presidential history waned.

And so, Trump went back to being, well, Trump. He tweeted more. He made calls -- on everything from foreign policy to staffing -- on instinct. Which brings us to the Jackson pick.

Trump didn't pick Jackson because of his depth of management experience in big organizations. (Jackson doesn't have that.) He didn't pick him after a long and deliberative process that included consultation with Republicans (and Democrats) on Capitol Hill. He didn't vet Jackson fully to ensure that he could even be confirmed. (Jackson was tapped as the top White House physician by President Barack Obama in 2013; that position does not require Senate confirmation.)

Trump picked Jackson because he liked him. Because he thought Jackson did a good job at that news conference announcing the results of Trump's physical. Because it felt like the right move.

All of that means that where the White House finds itself today with Jackson -- dead in the water unless something changes -- was entirely predictable. Governing by the seat of your pants is rarely a recipe for success; there's a reason, after all, that things like vetting exist.

Trump wanted Jackson because he liked him. Well, he got him. And I bet he wishes he didn't right about now.