The measure's opponents, including prominent business groups and the Colorado Chamber of Commerce, argue it will erode Colorado's competitive edge as the state's economy loses momentum relative to peer states. Gov. Jared Polis and Gov.-elect Phil Weiser also opposed the measure.

Speaking at a breakfast event hosted Tuesday by the Common Sense Institute, a business-aligned Colorado think tank, Henry Sobanet, treasurer of the Colorado State University System, described the reaction among opponents as a kind of shock. "I think we should just say 'Holy crap,'" Sobanet said. "That's kind of the first reaction. Go through the five stages of grief." He warned that the advantage Colorado has enjoyed relative to the rest of the country for decades is now at risk. "If we're going to be competitive, what do we do from here?" he asked, adding that the performance and effectiveness of how the money is spent "is going to be the coins of the realm."

The Common Sense Institute estimates the measure could reduce Colorado personal income by $200 million as high earners and businesses adjust to higher tax rates.

Scott Wasserman, a principal at political consultant Thinking Forward who has worked to place similar measures on Colorado ballots, said the vote does not signal a fundamental shift in the state's fiscal philosophy. He described a long-standing paradox in Democratic-controlled Colorado: lawmakers who advocate for better funding of healthcare, education and early childcare have lacked the money to deliver on those promises. "What I do think is that voters are taking Democrats up on their promise," Wasserman said at the same event. "It's possible that what voters are saying is like, 'All right, put up or shut up.'"

Wasserman cautioned that Democrats will face consequences if they fail to spend the new revenue wisely. "If they fail that test, I think that we will see voters take the state in a different direction," he said.

He also pointed to lingering tension between the business community and progressive Democrats after the bitter Amendment 87 campaign. "I think there's going to be a lot of hard feelings over how the business community opposed 87, and there's probably going to be a lot of reluctance to use the proceeds from 87 and what that does to the budget to help business with some of its needs," Wasserman said. "I'm hoping that everybody listens to their better angels and that people can come to the table and actually find a way forward. But I do think we're going to see a lot of sour grapes, a lot of tension there, and a lot of division about how these dollars get prudently spent."

Weiser has said he would work with the legislature to adjust the implementation of Propositions 134 and 135, two transgender-related measures that passed and that he opposed during the campaign. But John Zakhem, a partner at the Campbell Kill Brittan Ray law firm, told the panel he expects Weiser to take a different approach on Amendment 87. "He does not have the power to veto citizen-initiated legislation. So he can't change the law. He does have power, however, in coordination with the legislature to make amendments to the law," Zakhem said. "Now with respect to 87, my expectation, just knowing that it's the governor's party that passed 87, and maybe it's not his faction of the party that's put this on the books, I'll expect him to slow play any opposition in the courts. But I wouldn't bet on the governor taking the lead on that. Why pick a fight within your own party?"

The debate now shifts to how the new revenue will be spent and whether Colorado can preserve its business climate while fulfilling the promises voters endorsed.