BISMARCK, N.D. (AP) — Voters in North Dakota on Tuesday approved term limits for their governor and state legislators after a campaign largely funded by an outside term limits group and boosted within the state by far-right conservatives.

The ballot measure adds an article to the state constitution limiting lawmakers to eight years each in the state House and Senate. The governor couldn’t be elected more than twice.

Supporters said the measure will bring in new blood more often and increase voter participation. Opponents said term limits are an attack on the electorate’s right to choose its preferred candidates, and that more frequent turnover would diminish institutional knowledge and shift power to lobbyists, agencies and the governor.

Many Democratic and Republican lawmakers have spoken out against the measure. Republican Gov. Doug Burgum supported it.

U.S. Term Limits, a Washington, D.C.-based nonprofit that wants to pass term limits on all elected officials and whose Florida-based head has donated to Libertarian presidential candidates, contributed more than $810,000 in the past two years to get the ballot proposal before voters. Opponents of the measure have raised just over $40,000 to combat the proposal, with several contributions coming from Republican lawmakers, campaign finance disclosure records show.

The measure’s sponsoring committee includes several lawmakers linked to the Legislature’s ultraconservative Bastiat Caucus, as well as several new GOP district chairmen. It raised about $45,000 in addition to contributions from the out-of-state group.

Brooke Thiel, 35, an agriculture professor at North Dakota State University in Fargo and a self-described independent, voted against the measure. She said most lawmakers spend their first term just trying to figure things out and “once things get clicking” in their second terms she might want to vote for them again.

Meghan Friese, a 25-year-old nurse, voted in favor of term limits as she cast an early ballot in Bismarck. She said longtime incumbents are too difficult to defeat.

“Familiarity keeps them there,” she said.

The changes will take effect Jan. 1, but limits will not be retroactive — meaning the service of current officeholders will not count against them.

Fifteen states have term limits for legislators and 36 states limit the terms of governors.