Something both candidates in Virginia’s U.S. Senate race can agree on is the fact that opioid addiction has torn through the state, with 1,229 people dead from overdoses last year and thousands more in prison for crimes related to addiction.

Where Republican Corey A. Stewart and Sen. Tim Kaine (D) disagree is the cause behind the growing problem and how to fix it, differences the candidates have highlighted while touring areas of the state that have been hit hardest by what officials deemed a public health emergency in 2016.

Stewart, chair of the Prince William Board of County Supervisors, says Medicaid is to blame, arguing that it provides the drug at low cost to Medicaid patients who, he says, then sell it on the black market to addicts. He says Virginia’s recent Medicaid expansion — benefiting an extra 400,000 low-income patients — will make the problem worse. Stewart wants to require Medicaid recipients to pay more for their synthetic painkillers.

But he offers flimsy evidence to support his claims.

“Given the epidemic of opioid abuse in this country, we’re going to have to take some strong action,” said Stewart, from a county where 50 people died of opioid overdoses last year. “I would be for substantially increasing the co-pay for opioids for Medicaid recipients to help reduce the demand and contain the black market for drugs.”

Stewart’s theory echoes claims made by some Senate Republicans since January.

In response to those claims, a study published in the Journal of the American Medical Association last month found that the expansion of Medicaid under the Affordable Care Act allowed more people to receive opioid addiction treatment, instead of driving up prescriptions for synthetic painkillers.

In a blog post last month, Andrew Goodman-Bacon, an economics professor at Vanderbilt University, and Emma Sandoe, a Harvard University doctorate student in health policy political analysis, argued that there is no credible evidence that Medicaid expansion caused or exacerbated the opioid problem.

Stewart dismissed those arguments, saying that law enforcement officials he has met in southwestern Virginia told him there is a growing black market for Medicaid-reimbursed prescription drugs.

But a police sergeant in the Lee County town of Jonesville that Stewart cited as his main source told The Washington Post that he has no way of knowing whether that problem can be tied to Medicaid.

“For us to know exactly how they’re getting them, we don’t know,” said Sgt. Travis Mullins, who oversees narcotics enforcement in his town of 1,000 residents and sits on the Republican Party committee in the 9th Congressional District. “But the number of prescription pills we see being abused is really high.”

Kaine agrees that the abuse of opioids is rampant, contributing to 72,000 overdose in the United States last year, a record year for overdose-related deaths, according to the Centers for Disease Control and Prevention. Virginia recorded 1,391 deaths caused by overdoses last year, the majority related to opioids.

He argues for a mandate to bring opioid addiction in the country under control by 2030, comparing that goal to President John F. Kennedy’s call in 1962 for U.S. astronauts to set foot on the moon within a decade.

A bipartisan bill, co-sponsored by Kaine and pending in the Senate, would step up seizures of illegal opioids arriving at the U.S. border, push the National Institutes of Health to develop nonaddictive painkillers and fund more treatment programs, among other things.

In 1962, “being on the moon by the end of the decade seemed like science fiction,” Kaine said recently to a crowd in Alexandria. “Being addiction-free by 2030? The science is there. The question is: Is the will there? If society’s will is there, then we can do it.”

Kaine accuses Stewart of not caring enough about the opioid crisis, criticizing him during a July debate for skipping a vote by his county board over whether to allocate $200,000 in emergency funding toward treatment. Stewart was in Alabama that December day, campaigning for Republican Roy Moore in his failed Senate bid.

The measure failed 5 to 2, with the board’s Republican majority choosing to wait to learn what the state would allocate toward the crisis.

Stewart was present for another vote in April, when the board unanimously adopted a new spending plan that includes $430,000 to hire three therapists for addiction treatment.

Jodi Manz, Virginia’s assistant secretary of health and human resources, said any attention that results in more funding geared toward the crisis is welcome.

With the 1,229 deaths last year, opioid overdose deaths in the state have increased by 58 percent since 2007, state figures show.

Earlier this year, state officials ramped up efforts to bring those numbers down with $9.8 million in federal grant money that they anticipate will increase by an additional $15.7 million in the fall.

Among other things, the grant money is going toward drug interdiction, needle exchange programs and helping ex-convicts find addiction treatment, officials said.

Meanwhile, Gov. Ralph Northam (D), a pediatric neurologist, has toured medical schools in the state to lecture aspiring doctors on the importance of prescribing painkillers judiciously.

“Everybody has an aunt or someone else they know who ends up with 30 days’ worth of opioids that they don’t need and are just sitting in their medicine cabinet,” Manz said. “There is an opportunity for some of those pills to end up on the streets.”

Diane Engster, who listened to Kaine talk about his bill in Alexandria, said that was her concern when a nurse showed up with a bag of morphine and other opiates for her dying mother.

Engster said her mother, who died in February, did not really need the medication. And one bottle of Vicodin went missing, she said.

Engster said she still doesn’t know what happened to the drugs.

“They’re giving these drugs to people when they shouldn’t be, and it’s a danger to everybody,” she said.