Colorado’s flat-rate income tax is under attack — and if the perpetrators succeed, voters will open the gates to Trojan horses disguised as “fairness,” “priorities” and “progress.”

After two failed attempts, the title board approved Initiative 181 for signature-gathering. The measure would replace the flat tax Coloradans have enjoyed since 1987, when voters wisely abandoned graduated rates for a single, across-the-board system.

Now, so-called progressives want to drag us back to a graduated disaster. In the immortal words of Star Wars’ Admiral Ackbar: “It’s a trap!”

Colorado’s current universal tax rate is 4.4%. This measure would amend the state constitution to both permit and create graduated tax rates — billed as a tax break for lower- and middle-income earners.

Under the proposal, those earning $100,000 or less would pay 4.2%. Income from $100,001 to $500,000 continues at 4.4%. Sounds okay so far.

Not so fast.

Starting at $500,001, it hits 7.5%. At $750,001, it’s 8.5%. Then it hits 9.5% for every dollar above $1 million. That’s for individuals, couples and businesses alike.

Supporters call it “progressive” because rates progress from low to high — and that’s “progress” toward fairness. But this isn’t fair. Quite the contrary.

As the Gazette editorialized Tuesday: “Everyone pays their fair share right now under the state’s ‘flat’ tax because it’s the same proportion of everyone’s household income. Which also means the more you earn, the more you pay.”

Someone earning $75,000 pays $3,000 in tax while another making $250,000 pays $11,000 — both at 4.4% but with more money paid by the wealthier person, they point out. “Fair enough?” Absolutely.

It’s also simple, straightforward and pro-growth. But once we start down the graduated path, complexity, confusion and capital flight will dominate Colorado’s destiny.

On paper, it starts with five brackets. Sure, only higher earners would get hit at first — but more brackets will make future hikes and new brackets far easier. With a flat 4.4% rate, voters immediately grasp any increase. A jump to, say, 5.4% stands out.

But like the boiling frog, voters won’t feel the impact of each incremental tax hike until it’s too late. Cases-in-point: California and New York.

In fact, this proposal doesn’t index brackets for inflation — a silent tax increase that won’t trigger TABOR restrictions. It’s a tactic those deep-blue states use to generate billions.

By specifically earmarking the revenue to fund education, health care, child care and workforce programs, the initiative guarantees endless calls for “just a little more” — creating permanent constituency groups with vested interests in higher taxes.

Lawmakers could also change what counts as “taxable income” without voter approval — just as Democrats did this year to re-tax tips after Congress largely exempted them from federal adjusted gross income.

Establishing high-end tax brackets would make it easier to mount successful “tax the rich” campaigns under the “it won’t affect you” promise — the exact strategy advocates are employing to win over voters earning under $500,000.

Once high-end brackets exist, raising them — and eventually the other brackets — becomes an exponentially easier task. It also encourages untold special-interest tax carve-outs.

Do we really want Colorado’s tax code to be as layered and messy as the feds’?

Let’s be clear: This is merely the first step in the long-game to raise taxes and eliminate TABOR once and for all — regressing to a complex, unfair, outdated system that Coloradans abandoned nearly 40 years ago.

As Colorado already squeezes businesses with overwhelming regulations and prices families out of affording a home — and the energy needed to heat it — the last thing we need is to incentivize more Coloradans to flee with the businesses, income and investment capital we desperately need for our competitive edge.

Proponents claim this proposal will “recapture” money “the wealthiest Coloradans” will keep thanks to the Trump tax cuts by “reinvesting those dollars” in selected priorities — as if your paycheck is theirs to reclaim and existing programs generate an ROI in the first place.

Nonsense. Colorado has already proven what happens when the state gets a windfall. It was only a few years ago that lawmakers sat on a $3.6 billion surplus — and they squandered it. Now, with thinner coffers, they cry crisis and peddle historic tax hikes.

It gets worse. Under this initiative, the new tax revenue becomes a “voter-approved revenue change” under the Taxpayer’s Bill of Rights — exempting it from spending limits.

Colorado’s income tax currently generates roughly $17 billion annually. If the graduated income tax passes, revenue above that — an estimated $4 billion — wouldn’t hit TABOR limits. Instead, the state keeps every penny in a permanent, statewide “de-brucing.”

Let’s be real: This is just a giant tax, spend and CYA scheme wrapped in feel-good spending.

The graduated income tax is neither progressive nor reform. It’s an ambush. Once Colorado abandons its prosperous flat tax, the last guardrail against runaway taxation will collapse.

It must be stopped now — lest voters unwittingly spring the trap.

Jimmy Sengenberger is an investigative journalist, public speaker, and longtime local talk-radio host. Reach Jimmy online at Jimmysengenberger.com or on X (formerly Twitter) @SengCenter.