DENVER — Colorado's mercurial political nature was on full display Tuesday, with voters overwhelmingly approving taxes on marijuana sales but rejecting an income tax hike for schools.

The results suggest the state is in play for both political parties preparing for bigger races next year.

Democrats pushing a $1 billion income tax increase to overhaul the state's funding system for schools were dealt a resounding defeat, with about two-thirds of voters rejecting the proposal widely championed by the liberal establishment. Democratic Gov. John Hickenlooper, who's running for re-election in 2014, threw his political weight behind the education measure.

"What's going to come up immediately is the talk of the next year's governor's race," said Norman Provizer, a professor of political science at Metropolitan State University of Denver. "And whenever you're behind an initiative that fails, everybody starts thinking you're vulnerable."

Republican gubernatorial candidate Tom Tancredo used the proposal's defeat to attack Hickenlooper.

"The voters of Colorado are once again rejecting John Hickenlooper's agenda," the former congressman said.

Hickenlooper remained undeterred.

"We are committed to common sense solutions and remain committed to collaborating with everyone to make Colorado's education system the best it can be," he said in a statement.

On the flip side, a proposal to impose hefty taxes on recreational marijuana was an easy sell to voters. About two-thirds approved a 15 percent excise tax plus a 10 percent sales tax on pot sales that begin next year. The taxes are projected to bring in $70 million a year. The money will be used for school construction and regulating pot sales.

Voters may have found the pot taxes more appealing because many Colorado residents are not going to use marijuana, Provizer said.

Tuesday's results provided little indication of how the state will vote as Colorado prepares for bigger political races next year, including the governor's office and the U.S. Senate seat held by Democrat Mark Udall.

"We're still a purple state," said Steve Mazurana, professor emeritus of political science at the University of Northern Colorado.

Another thing that didn't change Tuesday was off-year voter turnout. About 1.1 million people voted in Colorado, according to results posted late Tuesday. That was up by just about 60,000 voters in 2011 despite passage of a new election law that allows same-day registration and requires that all eligible voters be sent ballots.