Prompted by a budget crisis and a Republican governor who has sided with the Democrats, the people of Colorado have spent this fall in a lively statewide seminar about the proper role of government in contemporary life.

The debate has been so passionate, and so even, that pollsters cannot predict a result in Tuesday's referendum election, when voters will decide whether to loosen the tight restrictions on state spending and taxes that were set 13 years ago when Colorado adopted its Taxpayer Bill of Rights, or Tabor, plan.

Gov. Bill Owens -- a onetime Tabor champion -- and other supporters of the change say the state will have to cut billions of dollars in spending on colleges, highways, parks and medical care if Tabor is not revised. Opponents of the referendum say cuts like that would be just fine, because individuals and the private sector should provide services such as higher education, transit and recreation.

The argument has national implications, particularly for Washington-based tax-limitation groups that have worked to sell similar tough spending restrictions to other states.

The national organizations are particularly incensed at their erstwhile ally Owens, a self-described "Republican conservative" who once had presidential ambitions. "Owens is finished on the national scene," said Grover G. Norquist of D.C.-based Americans for Tax Reform.

In Colorado, the intense argument has stayed away from personalities and focused more on philosophy -- that is, on each side's essential vision of the role state government should play.

The debate has been so serious that the voters -- who usually complain bitterly about campaign advertising -- say it has provided a valuable education. In a Denver Post poll, 81 percent of those surveyed said they had learned about government and about Tabor from the referendum campaign.

The specific point at issue is a provision of the Tabor system that makes it nearly impossible for government to increase spending, even when tax revenues are skyrocketing. This "ratchet" clause means Colorado can spend only a limited amount more in boom years than it spent in the austere days of the 2001 recession.

The result has been severe budget cuts: agriculture spending down 61 percent since 2001; transportation down 41 percent. State funding for public universities dropped sharply, and the University of Colorado Medical School now gets only 1 percent of its operating budget from the state.

Referendum C would eliminate the "ratchet," so that the state could spend more as revenue rose. A second ballot issue, Referendum D, would authorize a bond issue for roads, schools and pensions.

Owens says this amounts to "fixing a glitch in Tabor." Douglas Bruce, the small-government activist who wrote the Tabor plan in 1992, counters, "They want to 'fix' Tabor the way a vet would 'fix' your pet: render it impotent."

Colorado Democrats strongly back the change. Owens sided with them on the issue after the 2004 election, when voters dumped the Republican majorities in both houses of the legislature for failing to deal with the budget shortfall. The business community, most newspapers and moderate Republicans are also on board. But half the voters, polls show, remain unconvinced.

Supporters of the change are so worried that Democratic leaders convened a meeting at the state Capitol on Thursday to plan their strategy in case Referendum C is defeated.

At civic clubs, on talk shows, in letters to the editor, opponents of the change argue that government is already too expensive and intrusive. "Every cent that's taxed away decreases our personal wealth and eliminates our freedom of choice," Tom Hall of Louisville wrote in a letter to the Denver Post.

John Andrews, a former Republican state senator who is now a commentator on state politics, maintains that Coloradans don't want to live in a high-tax, big-government venue. "Those custodially smothered paradises of California, New York, Germany, and France are what Colorado's people would rather not be like," he wrote in his column earlier this month.

Andrews argues that universities should be funded privately and that tolls or fees should pay for roads and parks. He says that medical care should be left to "self-reliance" rather than "Big Brother."

But opponents of the spending limit say certain public needs can best be met by collective action.

"Do we want people carrying asphalt around to fill the potholes they see on the road?" asks Joan Fitz-Gerald, the Democratic president of the state Senate. "Should we tell them to set aside a spare room for some drug dealer, because we can't afford prisons? Do we want some guy in his basement teaching our medical students?"

The vote has been set for Tuesday because Tabor's authors included a provision saying any referendum to change the terms must be held on the "first Tuesday in November" -- not "the first Tuesday after the first Monday," the normal day for elections. That means Colorado will have another statewide election one week later to decide dozens of other ballot issues and local races.

Colorado Gov. Bill Owens, a Republican who has joined Democrats in support of easing limits on state spending, talks to a voter in Castle Rock.