Senate Majority Leader Mitch McConnell (R-Ky.) has made one thing clear: He thinks the best thing he can do for President Trump — and for Republicans' midterm election chances — is to push the Senate to approve as many of Trump's nominees as possible, as rapidly as possible.

So it's remarkable that the confirmation process for Trump's pick to lead Veterans Affairs, one of the largest and most politically high-profile federal agencies, is on hold. Ronny L. Jackson's nomination has raised concerns about the White House doctor's qualifications and oversight of White House medical staff, as well as allegations shared with the Senate about his dispersal of medication, a hostile work environment and possible incidents of drunkenness while on duty.

If there's one agency that Republican lawmakers want well-run, it's Veterans Affairs. Many of them have campaigned on getting their local VA offices in order. A VA pick by a Republican president and confirmed by a Republican Senate should normally be a slam dunk.

And yet Trump's pick to lead VA is imploding right before their eyes and for entirely avoidable reasons on the president's part.

First, Trump's White House did not vet Jackson, as The Washington Post's Josh Dawsey pointed out.

That means the issues holding up Jackson's nomination are likely to be new to the White House.

Second, Jackson doesn't have any experience running an agency, much less one of the largest in Washington.

Here's more or less how he got chosen for the job: Trump has been on a firing streak lately. In the past few months, he has fired his secretary of state, his national security adviser and his VA chief, David Shulkin (an Obama administration holdover whom Trump originally praised but then fired after questions were raised about Shulkin's business travel).

Each time, Trump made clear that a large part of why these people were ousted was because he didn't get along with them. He ended up replacing them with people he did get along with — choosing personality often at the expense of qualifications. Trump's secretary of state pick, CIA Director Mike Pompeo, will likely get confirmed this week by one of the narrowest margins in recent history for the nation's top diplomat, thanks in part to his lack of diplomatic experience.

In choosing a new VA chief, Trump seems to have picked someone he likes and who has said nice things about him on TV.

Jackson is best known in the Trump administration for effusively praising Trump's mental and physical health during a January news conference after Trump's annual physical. Jackson suggested Trump might live to be 200 years old if he ate fewer hamburgers and more vegetables.

That might explain why Republican lawmakers were lukewarm on Jackson's nomination when Trump announced it in March.

“I look forward to meeting Admiral Jackson and learning more about him,” Senate Veterans' Affairs Committee Chairman Johnny Isakson (R-Ga.) would only say.

Some major veterans groups were also concerned about Jackson's largely unknown positions and management style.

Now, Republican lawmakers are openly questioning Jackson's experience, receiving reports about his conduct as head of the White House medical office and outright halting his confirmation process.  On Tuesday, McConnell refused to back Jackson, saying he'd defer to the president — who minutes earlier had basically begged Jackson to drop out.

So, we have absolutely no vetting of someone completely inexperienced for the job of leading Veterans Affairs. Throw in the fact that the White House's own management style left them disorganized during a tricky confirmation process, and you have an (entirely predictable) perfect storm in which Jackson now finds himself.

The high turnover in the Trump White House means that the administration doesn't have a seasoned expert on veterans' issues. The Post reports that people involved in Jackson's nomination don't think the White House, which Congress often accuses of being disengaged, put its full weight behind persuading reluctant senators to approve the physician.

“He was walking into an ambush,” a veterans advocate close to the White House said of the Senate hearing, according to The Post. “He is just not ready.”

All of that is why, just days before Jackson was set to testify to the Senate, his confirmation process is suddenly on hold. That's remarkable coming from a GOP-held Senate whose leaders very much want to give a Republican president his preferred nominees, and who very much want VA to have a leader.

It suggests just how seriously Jackson's problems are, and, by extension, how incapable the White House is of nominating qualified people for the nation's top jobs.

Correction: A previous version of this report said that Sen. Johnny Isakson (R-Ga.) called the White House to express his concerns about Jackson. The senator's office said no such call was made. This report has been updated.