U.S. senators are growing frustrated over Donald J. Trump’s lack of vetting of Cabinet picks? Really? Well, who in the world knew?

The latest example of lax vetting comes to us via the president’s pick to be the next secretary of veterans affairs. Dr. Ronny Jackson’s nomination to lead the VA is in serious danger. Allegations have surfaced — from military sources — that Dr. Jackson has instigated a “hostile work environment” and has been drinking on the job.

Oops! Why didn’t the president’s team pick up on this?

Trump selected Jackson, an active-duty Navy rear admiral, because — apparently — he and the doc have a good relationship. The president likes and trusts the White House physician who has worked for two previous presidents. I suppose, therefore, that one could ask the question about “lax vetting” of Presidents Bush and Obama as well.

But the VA is a vast bureaucracy, the second-largest agency within the federal government. Jackson has zero administrative experience managing an agency of such size and magnitude.

As The Associated Press has reported: “The White House still seems to be feeling its way on the nomination process,” said Sen. Susan Collins, R-Maine, “and does not fully appreciate how important it is to do a thorough vetting and FBI background check on nominees.”

The president vowed to implement an “extreme vetting” procedure for immigrants entering the United States. I happen to support the principle of more rigorous examination of those seeking entry into this country.

Why, though, doesn’t the president impose an extreme vetting concept among those he selects for the highest positions in government? Indeed, a simple question or two could have avoided the hideous publicity surrounding Ronny Jackson’s nomination to lead the VA.

How about asking him something like this: Are there any workplace issues — anything at all — that might pose a problem for your nomination, Dr. Jackson?

Simple, yes?