Gov. John Hickenlooper and Democratic lawmakers say it’s a simple fix, but Republicans say it’s anything but.

As next week’s special legislative session approaches – it’s set to convene Monday – Republican leaders in the Capitol and outside pressure groups are ramping up their opposition and predict the endeavor will be an expensive waste of time.

It isn’t the reaction Hickenlooper expected when he issued a formal call for the session earlier in September so lawmakers could correct a drafting error in a tax bill that’s costing some special districts hundreds of thousands of dollars in revenue.

Senate Bill 267, sprawling legislation passed in the final days of the Legislature’s regular session this spring, inadvertently prevents some special districts – including the metro-wide Regional Transportation District and the Scientific and Cultural Facilities District – from continuing to collect retail sales tax on recreational marijuana, and everyone agrees it would just take a few words to restore their authority.

But Republican lawmakers don’t agree the Legislature can do that under the state constitution’s Taxpayer’s Bill of Rights, which they argue requires voter approval for a change in tax policy. On top of that, the conservative Americans for Prosperity organization planned to start running digital ads making the point Thursday, spending what state director Jesse Mallory said would be “five figures.”

“The constitution doesn’t make any distinguishing between an error, so-called, or an intended consequence,” Senate President Kevin Grantham, R-Cañon City, told Colorado Politics. “What happened was, there was statute, then there was a statute change – the result was an elimination of certain taxes, and the Legislature has one direction they can go when it comes to that, and that is removing them or eliminating them, but we can’t put new taxes in place.”

House Republican Leader Patrick Neville, R-Castle Rock, sounded the same note.

“What the governor’s pushing in this proposal is a clear violation of the constitution,” he told Colorado Politics. “It will result in a net revenue change to a district, which will require an election. It’s clear as day.”

House Speaker Crisanta Duran, D-Denver, said she was surprised by Republican objections.

“This was an unintentional omission that all the bill’s sponsors have recognized,” she told Colorado Politics. “It relates to a need to remove a tax exemption – we are well within our authority to make the change.” She added, “It’s a simple fix, and we should do our job.”

It’ll take the cooperation of at least a few Republicans to pass any legislation, since the party holds the majority in the Senate. Grantham said he was open to hearing arguments but wasn’t optimistic he’d be swayed.

“When I was told (the governor) had already drafted a letter and was rolling it out, I expressed my, I guess I could call it disappointment,” Grantham said. “I told him, don’t expect any cheerleading from our side. We were unhappy about how it happened. I didn’t want any expectations that we were on board with his spending $25,000 a day to bring us back in.”

Under the Legislature’s rules, a special session has to last at least three days in order to provide enough time for any legislation that’s introduced to be heard in both chambers – another amendment to the state constitution requires bills at least receive a committee hearing – at a cost officials estimate at between $20,000 and $25,000 a day.

“I would like to get out of here as quick as possible and stop wasting taxpayer money,” Neville said.

In his office this week, Hickenlooper told Colorado Politics he was blindsided by the GOP backlash and arguments over TABOR.

“This shows where I’m not a very seasoned politician,’ Hickenlooper said. “I assumed since the General Assembly made a mistake in the drafting of the legislation and our office – we saw that bill and through our budget office we missed it – so it’s our mistake as well. We all made a mistake.”

“Where I come from, if you make a mistake you do three things: One, you admit you made a mistake; two, you apologize for; and, three, you try to fix it. So I just assumed this would be a no-brainer.”

The governor expressed astonishment.

“What? Why would you do this? This has nothing to do with TABOR. People voted for this tax. What possible connection could there be?

“Now that I know this could happen, clearly there are many things I could have done, right?”

But he intends to push ahead.

Mallory was the Senate Republicans’ chief of staff last session. The timing is part of the backlash, he told Colorado Politics. Since Senate Bill 267 moved the hospital provider fee out from under a TABOR spending cap (and got that cap lowered by $200 million in the bargain), it could have been handled more cautiously, he said.

“The frustrating thing is, why is it an emergency now when it wasn’t months ago, knowing there was a TABOR issue they could have gone to the ballot?” Mallory said, echoing a question Grantham also pressed.

Duran acknowledged that officials have been aware of the problem since June and were considering waiting until the next session starts in January to put together a fix, but said the special districts only determined recently that they would have trouble absorbing the loss until next year.

“I’ve been surprised before there,” Mallory said of the Capitol fray. “But when so many legislators lash out on social media saying nobody bothered to call them or talk them, I think the well is so poisoned there that I’m hard-pressed to think anything happens.”