SIOUX FALLS, S.D. — Supporters of ballot measures on crime victims’ rights and labor union fees are dominating political advertising on television in South Dakota ahead of the November election.

Through Monday, backers of a measure that would incorporate victims’ rights into the state constitution have spent roughly $161,000 on broadcast TV ads, while a labor-backed ballot measure that would allow unions to charge fees to nonmembers has benefited from over $146,000 in ads, according to data from the Center for Public Integrity.

The two campaigns account for nearly all such spending in South Dakota. The center’s information offers key insights into political expenditures made since the last state campaign finance disclosure deadline for ballot question committees in May.

Statewide advertising will play an important part in educating voters about the victims’ rights constitutional amendment, Marsy’s Law for South Dakota Chairman Jason Glodt said.

The law is named after Marsalee “Marsy” Nicholas, who was killed by her ex-boyfriend in 1983. Her brother, Henry Nicholas, is bankrolling an effort to expand it into more states. Nicholas has put roughly $800,000 toward the South Dakota campaign.

The Marsy’s Law ballot initiative, named Amendment S, would establish constitutional rights for crime victims including privacy, protection from harassment or abuse, and timely notice of trial, sentencing and post-judgment proceedings. Victims would have the right to be notified of the escape or release of the accused. The proposal would require that victims are notified of their rights, which would also include the opportunity to offer input during the case.

Supporters say the measure would elevate victims’ rights to ensure they have protections similar to criminal defendants. Foes argue Marsy’s Law would bog down the system for victims while increasing court-related costs. They say many of the rights included in the amendment are already in state law.

“If it was a real problem, they would not need to spend $800,000 in South Dakota to expose it,” said opponent Ryan Kolbeck, president of the South Dakota Association of Criminal Defense Lawyers.

Supporters of the union-backed ballot measure need to inform voters to overcome the negative public sentiment toward labor organizations in South Dakota, said Jason George, special projects director at the International Union of Operating Engineers Local 49, which is the main backer of the measure and has members in the Dakotas and Minnesota.

Initiated Measure 23 would allow a labor union that has a collective bargaining agreement with an employer to charge fees to non-union members covered under the contract for services such as representation during the grievance process.

“It’s a lot easier for the opponents” of the measure, George said. “All they have to do is say, ‘This is a big bad union initiative. Vote against it.'”

Opponents argue that the plan would allow unions to circumvent South Dakota’s right-to-work law. Foes hope to spend more than $100,000 on television advertising, said opponent David Owen, president of the South Dakota Chamber of Commerce and Industry.

The Center for Public Integrity analyzed data about political advertising on broadcast television from Kantar Media/CMAG, a media tracking company that monitors 211 media markets around the country and offers a widely accepted estimate of the money spent to air each spot.

These figures cover ads aired through Monday, yet represent only part of the money spent on political advertising. They do not include ads for radio, online, direct mail or TV ads that ran on local cable systems. The estimates also do not include the cost of making the ads.