Donald Trump’s ignorance about the federal government was on full display at a campaign rally.

The president promised a 10 percent tax cut before the midterm election. Cheers erupted from the crowd.

Oh, but wait. Congress initiates tax measures. Congress isn’t meeting. The president cannot enact a tax cut by himself.

Cutting taxes is a complicated matter. It requires negotiation among lawmakers and with the White House.

So it is that Donald Trump has shown us yet again that he doesn’t know what the hell he’s doing. He can say things. He can elicit cheers from adoring crowds.

He cannot deliver anything by himself. None of this matters to his base. This is the “new normal” in Washington: A president doesn’t know what he’s talking about … and neither does the crowd that cheers him on.