I thought a Trump adviser could explain his tax plan. I was wrong.

Ruth Marcus
Ruth Marcus ©James Kegley

One of Donald Trump’s chief policy mysteries is how he intends to do the arithmetically impossible: reduce taxes by trillions of dollars; shield Social Security and Medicare benefits from any cuts; “rebuild” the military and infrastructure; and – depending on what day Trump is talking – start to pay off the national debt, if not eliminate it by the end of his second term.

Perhaps, I thought, Sam Clovis, Trump’s national co-chair and chief policy adviser, could explain. Clovis, an economics professor at Morningside College, was Trump’s emissary to a fiscal responsibility summit Wednesday.

To say the session was unedifying fails to convey its incoherence.

Interviewed by CNBC’s John Harwood, Clovis started by misstating Trump’s tax plan’s cost and went downhill from there.

Harwood noted the Tax Foundation, which Clovis described as a “highly credible organization,” estimated the Trump tax plan’s cost at $10 trillion over 10 years – even under dynamic scoring (giving the plan credit for spurring economic growth).

Clovis: “That’s not entirely true, because the Tax Foundation model is a static model. It’s not a dynamic model.”

Harwood: “They do it both ways, but I believe that their $10 trillion figure that they came up with was in their dynamic model.”

Clovis: “Well, that’s what they told me, and I sat across the table from them just like this, John.”

The Tax Foundation puts the “dynamic” cost of Trump’s plan at $10.1 trillion. The “static” score is $11.9 trillion.

Clovis’ fiscal insouciance was breathtaking. “Our proposals, what we think will happen, will lead us in fact to about a $4.5 to $7 trillion surplus at the end of 10 years, if all of our initiatives are put in place,” he said.

Pause to appreciate the audacity of this claim. The Congressional Budget Office estimates deficits will total another $9.4 trillion during this period. So Trump is purporting to pay for his $10 trillion tax cut, eliminate that additional deficit and amass a surplus amounting to several trillion more?

Then there was Clovis’ puzzling answer to Harwood’s questions about whether Trump – who has vowed not to cut entitlement benefits – might back away from that pledge once in office.

Clovis said, once the Trump-generated economic growth takes off, “we’ll take a hard look at those to start seeing what we can do in a bipartisan way.”

Still, Clovis said, “Right now, we’re not going to touch anything because we can’t predict the growth. If we don’t have that growth, then I think that whoever is the next president is going to have a horrible time in dealing with this, because those entitlements will race to the front of all the economic issues we have in this country.”

If Trump is open to entitlement reform, I think that’s good news. But who can tell what Trump position is real and what is illusory?