Larry Kudlow’s Twitter feed sent me to this critique of Rubio’s economic agenda by Rich Danker.

It’s an idiosyncratic take: Danker wants to present his critique as a supply-side challenge to Rubio, but he also blasts the Lee-Rubio tax-reform plan for cutting taxes on investment–which is a priority for most supply-siders. Danker claims that Rubio has “mostly stuck to low-risk proposals like fast-track trade authority and ending the oil export embargo,” which is a bizarre characterization. Rubio ran on Social Security and Medicare reform in the American state with the highest median age. He has outlined proposals on everything from replacing Obamacare to transforming the safety net to changing the way higher education is financed. And whether you like or dislike the immigration reform he championed two years ago–and I mostly disliked it–you can’t say it was “low-risk.”

Danker is also, in places, just wrong. Danker claims that Lee-Rubio involves “raising taxes on many small businesses” because “pass-through income would be taxed at a flat 25%.” No, it wouldn’t: That’s the maximum tax rate a business would face. A lot of businesses would pay 15 percent. (See p. 8 here.)

His political analysis does not make much sense, either. “It’s implausible that this tax plan will excite Republican voters because most won’t understand it or see much benefit from it. There’s little for them to get excited about in a plan that would leave the top rate practically unchanged. . .” Most Republican voters, like most other voters, do not pay the top tax rate. They would not directly benefit from Lee-Rubio’s reduction in that top rate, nor would they directly benefit from a proposal to cut it further. Because of its other provisions, however, Lee-Rubio would leave almost everyone paying a lower tax bill. Every married couple making between $75,000 and $150,000 a year would see a 10-point drop in its tax rate, for example. Taxpaying parents would see an increase in the child credit.

Danker also raises a political caution about zeroing out the capital-gains tax, which Lee-Rubio proposes to do. I think he overstates this concern by invoking the decline in the percentage of Americans owning stock — it has fallen only four points from its peak, from 53 to 49 — but it may well be that a 0 percent capital-gains tax rate is politically unrealistic. I like the basic structure of the Lee-Rubio plan, but there is certainly plenty to argue about in it. Continued argument might even improve the plan, so long as that argument is based on an accurate understanding of it.