Top Democratic lawmakers want to ask Colorado voters this November to permanently set aside the spending cap in the state’s Taxpayer’s Bill of Rights.

House Speaker KC Becker is drafting a measure to put a question on the 2019 ballot that would allow the state to keep as much as $960 million in projected revenues through June 2020 — money that otherwise would get refunded to taxpayers. The proposal would split the dollars evenly between K-12 education, higher education and transportation.

But now Democratic Gov. Jared Polis is not sure it’s the right strategy — or that it can pass.

“Going to the ballot in 2019 is possible, but it’s premature to say that it is the right strategy at this time,” Polis spokeswoman Laurie Cipriano told The Colorado Sun on Wednesday. “The governor wants to ensure that if he supports a ballot initiative that it’s set up for success.”

The dispute only further complicates the party’s effort to rollback TABOR, the state’s unique constitutional restriction on spending that is one of most volatile issues in Colorado politics. And it once again pits the governor against lawmakers in his own party early in his term.

The move to eliminate the TABOR cap still is a top priority for Polis, who pledged as a candidate to build support for the idea, and Democratic legislative leaders who have worked behind the scenes on the issue for weeks.

The lawmakers even consulted new polling data and considered on whether to seek another temporary timeout or push for a permanent pause, settling on the latter approach and a push to the ballot this year.

But it’s not clear how Polis’ stance will stymie the effort. A spokewoman for the governor said he “will continue to work with stakeholders” on the issue. Becker did not return messages seeking comment Wednesday.

The Boulder lawmaker won big applause at a recent town hall when she announced she would take the measure to the ballot in November. “I’m asking voters ‘Can you let the state keep the revenue we are already collecting?’” Becker told the crowd.

The question would not touch the TABOR requirement that voters approve any proposed tax hikes. But it still represents the most substantial overhaul in years, and regardless of when it makes the ballot, it is expected to draw fierce opposition from conservative organizations, who began organizing a coalition months ago to defend TABOR.

“This is just another way for legislators to try to get more tax money after they’ve been told “no” by voters over and over,” said Michael Fields, the executive director at Colorado Rising Action, an advocacy organization that is part of the coalition. “Coloradans will simply see it as a tax increase.”

MORE: A citizen’s guide to how TABOR and spending works in Colorado.

How the TABOR overhaul would work

The latest effort to address TABOR comes more than a decade after voters approved a five-year timeout on the state’s revenue limits and raised the cap on spending as part of Referendum C. The Democratic-controlled General Assembly put the measure on the ballot with support from then-Gov. Bill Owens, a Republican.

The move — known as “de-Brucing” in reference to TABOR’s author Douglas Bruce — passed with 52 percent in 2005. It allowed the state to spend an additional $3.6 billion in revenue over the cap, according to the Colorado Fiscal Institute. But a companion measure to issue bonds for transportation and other needs failed.

Carol Hedges, the fiscal institute’s executive director, supports the new effort. She said the constitutional amendment’s restrictions hurt the state’s ability to balance the lows of a recession and the highs of a booming economy.

“This is just a very fiscally prudent thing to do,” Hedges said. “It’s not about growing government, it’s about letting the state legislature manage the financial resources of the state.”

Under TABOR, which voters put in the constitution in 1992, the annual increase in the state’s revenues — and thus its spending — is limited to population plus inflation growth.

Any money collected over the cap is returned to taxpayers through a tiered system depending on the amount of the refund. The first dollars go toward the senior homestead and disabled veterans property tax break, and remaining excess revenue could trigger a sales tax refund and temporary reduction in the state’s income tax rate.

The most recent refunds came in fiscal year 2014-15 and resulted in a modest refund the following tax year. But TABOR also allows lawmakers to seek voter approval to retain any revenue that exceeds the cap for any length of time — which is what many local governments have done and now Democrats want to do at the state level.

The legislative economic forecast from December expects state revenue to exceed the TABOR cap by $609 million from the current fiscal year through June 2020. The governor’s budget forecast projects as much as $960 million in revenue that would get returned to taxpayers.

If the referendum does not succeed, the estimated refunds for single tax filers could total $232 over the next three tax years, according to the Governor’s Office of State Budget and Planning. The refunds for joint filers would reach $597 in the same period under the higher projections.

The figures, which do not include the property tax break, are subject to change when new fiscal estimates are released in mid-March.

A different political dynamic adds a question mark

One major difference from the successful referendum in 2005 is the lack of support so far from a big-name Republican. The decision to make it permanent also would heighten the political stakes, and conservative organizers believe it makes it easier to defeat at the ballot box.

“I don’t think you’re going to have much if any Republican support, especially if it’s permanent,” Fields said.

State Rep. Rod Bockenfeld, a Republican on the House Finance Committee, is approaching the TABOR measure with skepticism.

“Down here there’s a lot of money, it’s all about priorities,” the Watkins lawmaker said. “And if you can reprioritize spending, there is more than enough money to be chipping away at the state’s needs. You don’t have to grab it all overnight.”

Hedges, an expert on TABOR and former policy director for Democratic Gov. Roy Romer, said the key is to show how who it will benefit.

“I think it’s always important to show that all different kinds of communities are going to benefit from a statewide proposal,” she said.

The pressures of TABOR on spending are far-reaching. And in 2017, lawmakers approved legislation to exempt fees paid by hospitals from counting toward the revenue caps. The move sparked a lawsuit from conservative critics, who believed it should go to the ballot for voter approval. A Denver District Court judge on Wednesday dismissed the legal challenge.