The White House reaction to David Shulkin’s departure as veterans affairs secretary prompts a question from yours truly.

Donald Trump is moving “closer” to fielding an ideal Cabinet, the White House press office said after Shulkin submitted his resignation — apparently at the president’s request.

So, the question is this: Why didn’t the president pick an ideal Cabinet when he was transitioning into the office in late 2016 and early 2017?

Shulkin is the eighth Cabinet officer or close White House adviser to quit or be fired in just 15 months into the Trump administration. They’re dropping like flies in the West Wing and in agencies throughout the executive branch of the federal government.

The president vowed to surround himself with the “best people” as he was forming the executive branch leadership. If we are to believe the White House’s latest assertion about Trump’s desire to move closer to an ideal Cabinet while filling key White House advisory posts, then are we also to assume that the president has failed in keeping this particular promise?

Admiral Ronny Jackson, the White House physician, is the new nominee to lead the Department of Veterans Affairs; Jackson has examined the past three presidents and delivered a sparkling medical critique of Trump’s physical health. That’s fine. I’m sure he’s a fine doctor. He does lack governmental administrative experience, although I’ll endorse the president’s assessment that as an active-duty military officer, Admiral Jackson has a keen understanding of veterans issues. I wish him well.

I want to circle back to my original question: Why didn’t the president select a top-tier roster of Cabinet officials and critical White House advisers when he took office?

Oh, I forgot something. That requires a president to do his homework and to rely on the best advice from the “best people” he has assembled to make these critical decisions at the outset.

Or, to put it another way: The president should have employed some “extreme vetting” techniques in assembling his team.