For one bright shining moment last fall, Art Laffer, the idiomatic godfather of supply-side economics, was held up as something of a hero (reluctantly and haltingly, to be sure) by the Colorado Democrats and the state’s center-left. The cause of this momentary embrace of economic sunshine and reason? Dr. Laffer’s unfortunate endorsement of Proposition HH, culminating with his appearance beside his old friend Gov. Jared Polis on a televised debate with now-House Minority Leader Rose Pugliese and Michael Fields, in which Pugliese and Fields tried to remind the good doctor of his own economic philosophy.

Dr. Laffer made a number of uncharacteristic mistakes during that debate, but he did make a very profound point (which, incidentally, had the debate been governed under conventional debate rules, would have been considered a fatal concession). He said at one point that tax refunds, such as those provided for under the state’s TABOR formula, are not the crucial catalyst of economic productivity and growth — reductions in the tax rate are.

In other words, letting people keep a greater percentage of what they earn is more economically beneficial than later returning money that was taken in the first place — especially if that money is redistributed broadly rather than simply returned from whence it came. It is the one economically valid argument against the structure of TABOR.

The more interesting part of that night, however, was not the criss-crossing of economic arguments, but the acknowledgment by Gov. Polis that he (mostly) agrees with his friend Dr. Laffer, and his two debate opponents, that the income tax is inherently damaging to the economy (you don’t tax what you want more of) and ought to be eliminated, or at least reduced until such time as popular disposition can wrap it’s head around a 0% state income tax.

Well, Pugliese ran with that ball, and accordingly ran a bill, HB-1065, with the assistance of Colorado Springs populist firebrand Rep. Scott Bottoms and venerable Republican Sen. Barbara Kirkmeyer, to do just that; reduce the state income tax modestly from 4.4% to 4.0%. That proposal died a predictable death in House Finance Committee earlier this week.

Stay up to speed: Sign up for daily opinion in your inbox Monday-Friday

Here we see how the jagged intersection of politics and policy can become unnavigable. There are plenty of good ideas that come from that building that are bipartisan. But some of the best ideas are doomed upon conception simply because the “wrong” party offers them. It’s unfortunate, yes, but a reality of our political system. If George McGovern or Teddy Kennedy had proposed, say, a pro-growth tax reduction bill, or a measure to strengthen our defenses against the Soviet Union, would Ronald Reagan have embraced them? We’ll never know, because McGovern and TKennedy rarely, if ever, had a good idea between them in their entire public lives, but you see the dilemma.

The political gamesmanship aside, the policy itself is a good one. It is a common fallacy, one repeated during the summary execution of HB-1065, that rate reductions directly correlate with reductions in revenue, and thus necessitate cuts in public services. It can be argued just what services ought to be public, and what ought to be their scope, reach and depth, but the fact remains the realities of economics dictate tax rates can be cut without having to cut public-sector services. Laffer himself explained it best, with his eponymous Laffer Curve. A contemporary of Laffer’s, the economist George Gilder, wrote Laffer “showed that lower tax rates can so stimulate business and so shift income from shelters to taxable activity that lower rates bring in higher revenues.” And so they do, and have, every time they have been tried.

That may not be the case if the money retained by the taxpayers in question remains comatose, but of course it does not; if it is not being invested as pure capital — bankrolling a new building, say, and engaged in paying wages and buying concrete — it is sitting in banks or invested in equities or bonds, where it is financing further economic activity. Does a 0.4% tax reduction benefit, in arithmetic terms, the person making $500,000 more than the person making $50,000? Sure, in the same sense that the tax itself hurts Mr. Moneybags more; $2,000 is more than $200. But that $2,000, one way or another, generates economic activity, which increases productivity, which in turn increases the state’s gross domestic product. That translates into an increase in income for all, including the person making $50,000 or less.

If economic productivity and higher incomes are the goal, then it makes no sense to tax productivity and income growth; accordingly, a policy offering relief from those tax burdens is a good one, whichever party the person offering that relief belongs to.

Kelly Sloan is a political and public affairs consultant and a recovering journalist based in Denver.