It has become easy to understand Donald Trump’s affection for coal miners. The president and the miners work underground — and each week Trump finds a way to descend to new depths.

As Trump heads to Florida on Wednesday for a “listening session” with students, it is important to remember the president’s most egregious recent mouth-off session.

That was his inflammatory Saturday tweet in which he suggested that the FBI could have prevented the Parkland massacre if the Bureau were not “spending too much time trying to prove Russian collusion with the Trump campaign.”

The Republican attacks on Trump for implying that the FBI has blood on its hands were delivered in the muted tones of a parent not wanting to wake a sleeping baby.

Typical was South Carolina Sen. Tim Scott, who took pains to say on “Face the Nation” that the Florida shooting and the Russia probe were (drum roll, maestro) “two separate issues.” Only outgoing Ohio Gov. John Kasich — who represents a branch of the Republican Party that may no longer exist — had the gumption to tell CNN that Trump’s tweets were “absurd.”