The group behind a ballot measure aiming to cap the state’s income tax at the current rate has submitted signatures from voters to election officials for review, part of the tug and pull in Colorado between opposing political forces fighting over state revenue.

That fight is taking shape as the contending sides push their diametrically opposed ballot measures. One side has long sought to raise more revenue, arguing what the state collects is insufficient to pay for services and programs. The other side counters that a flat tax is fair to everyone, producing sufficient revenue for state spending, and what policymakers need is fiscal discipline.

Backed by Advance Colorado, Initiative No. 232 would cap Colorado’s individual and corporate income tax rate at 4.4%. That rate has been in place since 2022.

The group said it submitted 190,000 signatures to the Secretary of State’s Office. The proposal needs just over 124,000 valid signatures to appear on the ballot.

“This is a clear counter to the far left’s attempt to hike taxes in Colorado, price people out of the state we love, and drive business out. We’ll always fight to protect TABOR and keep our taxes low,” Michael Fields, executive director of Advance Colorado, said in a statement.

Colorado is one of 15 states with a flat income tax rate, meaning all taxpayers pay the same percentage of their income regardless of how much they make.

The alternative is a graduated or progressive tax rate, which a coalition of progressive groups is pushing to put on the November ballot.

Initiative No. 195, backed by the Denver-based think tank Bell Policy Center and a coalition known as Protect Colorado’s Future, would establish a graduated income tax, in which individuals and businesses would be taxed differently based on their earnings.

For example, those who make over $1 million a year would see an increase from the current flat income tax rate of 4.4% to 8.41%, while those earning under $25,000 would see a reduction to 3.71%.

The measure would result in lower income tax for 97% of Colorado residents and 95% of businesses, insisted the Bell Policy Center.

Critics said the measure is a tax hike of billions of dollars, with the majority seeing a tax cut of only a few hundred dollars while higher-income earners would pay the state government tens of thousands more.

The federal government uses a graduated income tax rate, as do several states, including Minnesota, Wisconsin, California and Alabama.

The graduated tax proposal is anticipated to increase the tax base by $2 billion, depending on which proposal ultimately ends up on the ballot. The new revenue would be used for K-12 education, healthcare and early childcare and education, according to the proponents.

A debate between Fields and Chris deGruy Kennedy, president and CEO of the Bell Policy Center, erupted on X on Thursday.

“This only protects the 3% of Coloradans and 5% of corporations (most of which are out-of-state) making more than $500,000 per year from a tax increase,” deGruy Kennedy said on the social media platform.

“Everyone else is set to get a tax cut from the grad inc tax proposal,” he added.

“The progressive tax hike,” countered Fields, “would increase taxes on seniors and military veterans.”

“This measure says, ‘Any income tax law change after July 1, 1992 shall also require all taxable net income to be taxed…’ It would put in the state constitution a strict mandate that the state must tax all income,” he wrote. “This means that state deductions will be taken away and taxes will be increased on Colorado’s seniors, retirees, and military veterans.”

“False,” deGruy Kennedy replied. “It says ‘to be taxed with no added surcharge.’ You can’t just leave out part of the sentence.”

Kathy White, the executive director at Colorado Fiscal Institute, which supports the measure, earlier argued that Colorado’s working families “shouldn’t have to pick up the tab so the wealthiest get a $71,000-a-year gift from Congress — especially when TABOR has already tied our hands for decades.”

Meanwhile, Jake Fogleman of the Independence Institute, which has persuaded voters to reduce Colorado’s income tax rate, earlier said a flat tax offers several advantages, notably making tax filing “simpler and more predictable.”

A single tax rate, he wrote, also “prevents schemes to impose concentrated costs on small groups of residents.” 

“Thus,” he said, “the flat tax acts as a powerful political disincentive against policymakers making routine requests for higher taxes.”

Protect Colorado’s Future has not yet submitted its signatures to the Secretary of State’s Office, but it has until Aug. 3 to do so. To qualify for the ballot, initiatives must receive just over 124,000 valid signatures.

If both initiatives are approved, the one with the higher vote total would take effect. That means a victory for Initiative 195 would move Colorado to a graduated income tax system, while a win for Initiative 232 would allow income tax cuts but prohibit increases.