Americans for Prosperity, the conservative group financially backed by the Koch Brothers, is targeting Sen. Mark Pryor, D-Ark., with a new ad highlighting his position on Obamacare, increasing its ad spending in the Arkansas Senate race to over $1.8 million.

The minute long ad features a man named Jerry, who runs a trucking business and is frustrated with the uncertainty of his health care coverage due to the Affordable Care Act.

"It's like living in a haze. You don't know whether you're going to have insurance or whether you're going to be able to afford your insurance. It was taken away from us, or it was given back to us, or it was taken - we don't know what it's been now," Jerry says in the ad. "I think the American people are tired of this constant angst, this constant crisis, they want certainty in their lives."

"Mark Pryor voted for this law. He hasn't been that responsive to the issue now. Do you think he'll be responsive four years from now, or two years from now? There's just this silence," he says.

Jerry's wife Wanda, who was the focus of AFP's last ad against Pryor, makes a cameo in the spot. AFP said they wanted to highlight two different perspective of how the Affordable Care Act impacts families.

The commercial will run across Arkansas starting Tuesday for three weeks backed up by $540,000 ad buy.

"Instead of bringing Americans peace of mind about their health care, ObamaCare is wreaking havoc on Americans from all walks of life," AFP President Tim Phillips said in a statement. "Jerry's story is not unique. Millions of Americans all across the country have been frustrated and let down by a law that was sold on a foundation of broken promises. It is disappointing that Senator Pryor has chosen - time and time again - to stand by a barely-functioning piece of legislation rather than the people he represents in Arkansas."

The Pryor campaign said AFP's latest ad buy is a sign of desperation.

"The Kochs are getting desperate," Erik Dorey, a spokesman for the Pryor campaign, told ABC News. "They're throwing millions at Congressman Cotton to reward his reckless votes against Medicare, student loans and equal pay for women, but Arkansans just aren't buying these misleading attacks."

AFP has maintained a forceful presence on the Arkansas airwaves this year. Pryor is facing a challenge from Rep. Tom Cotton, R-Ark., who is backed by establishment and Tea Party groups alike. The conservative group ran $700,000 worth of ads against Pryor in March and made a $606,00 ad buy in February.

This post has been updated.