North Dakota voters resoundingly defeated an attempt to abolish the state’s property taxes Tuesday and were set to allow the University of North Dakota to rename its controversial mascot, which critics say denigrates Native Americans.

More than 70% of voters rejected a grass-roots effort to eliminate state property taxes, according to unofficial returns, even though North Dakota has a budget surplus that exceeds $1 billion, in part due to an oil boom. More than 27,000 residents had signed a petition to get the measure on Tuesday’s ballot.

“North Dakotans have a long history of rejecting extreme measures that take a big leap in policy,” said Jon Godfread, a North Dakota Chamber of Commerce official who was part of a widespread coalition to defeat the measure.

Charlene Nelson, a stay-at-home mother of three who headed a citizen group called Empower the Taxpayer, said too many North Dakotans were losing their homes because of runaway property taxes.

“We started this movement before the oil boom,” she said earlier Tuesday. “But this isn’t about being flush with oil money. It’s based on principle. Property tax rates are rising faster than people’s ability to pay them.”

Nelson said the cuts could be made without raising other taxes. “Proceeds from the oil boom are $4 million a day — it’s mind-boggling. We don’t need this tax.”

But opponents contended that eliminating property taxes would cost the state $812 million and leave no alternative but to raise taxes elsewhere.

“We’re all for tax reform, but this was simply a misguided plan without a plan,” Godfread said. “The lost tax money would have to come from somewhere. It would have left officials with a mandate to double or triple other taxes. So who wins by that move?”

North Dakota voters also empowered the University of North Dakota to drop its Fighting Sioux mascot, which the National Collegiate Athletic Assn. and many others have called offensive.

That bitter debate squared off along unusual battle lines. Some alumni argued it was time for the moniker to go, saying that some schools had refused to play the university, and that some athletes had rejected scholarship offers out of distaste over the mascot name.

But some Native American tribes had advocated keeping it, saying the name brought attention to the plight of local reservations.

The university first used Sioux as its nickname in the 1930s. Decades later, it added “Fighting,” which helped to ignite the controversy.

john.glionna@latimes.com