Seeking to blunt criticism of Rep. Jacky Rosen, a progressive opposition research firm found that Sen. Dean Heller had also missed a vote as a House member on legislation that helped veterans deal with the medical issues associated with exposure to Agent Orange.

The conservative group One Nation, which was launched by Karl Rove in 2015 and is aligned with Senate Republican Leader Mitch McConnell, this week unveiled an ad running in Las Vegas that painted Rosen, a Democrat who is running for Senate against Heller, as insensitive to those ailing veterans after she missed a vote in June on a bill designed to help them.

"In case you needed more proof that wealthy special interests will say anything to help keep Heller in their pocket, Heller has missed a vote on the exact same issue his allies are attacking his opponent on,” said Joshua Karp, a spokesman for American Bridge 21st Century. “These guys are desperate and will say anything to score partisan points, even if it means playing politics with our veterans."

Representatives from One Nation and Heller’s Senate campaign declined to comment.

American Bridge pointed to a vote on July 27, 2010, that Heller, a Republican, missed while serving in the House. The chamber approved a supplemental spending bill that funded the surge of troops in Afghanistan and $13.4 billion to provide additional benefits for veterans exposed to Agent Orange in Vietnam. Heller missed all six votes on that day.

The reason: Heller attended the funeral of former Gov. Kenny Guinn, which was held in Las Vegas on the same day.

Vietnam veterans are an important constituency in the state because of their numbers and because any problems they suffer also can affect their spouses and offspring. More than 40 percent of the state’s 200,000 veterans are 65 or older, and of that cohort, more than 30 percent served in Vietnam, according to the U.S. Census Bureau.

The measure Rosen did not vote on would extend medical benefits to Navy veterans who spent their tours of duty along the coastlines of Vietnam to treat Agent Orange-related illnesses. The legislation passed the House with an overwhelming 382-0 vote and now awaits action by the Senate. Some 45 members didn’t vote.

Rosen was at the U.S. southwest border the day of the vote to gather information about children separated from their parents under President Donald Trump’s now-suspended family-separation policy. Her campaign released an ad shortly after the visit.

Rosen’s campaign dismissed the allegation, saying that she had been an early supporter of the measure.