DENVER — When Republican Congressman Cory Gardner launched his U.S. Senate campaign in late February, he talked almost exclusively about his Democratic opponent’s support for Obamacare.

Since then, Obamacare has receded a bit as a GOP attack line as polling has indicated that Obamacare-related attacks aren’t getting much traction with voters.

On Monday, Gardner’s campaign launched its latest TV ad, which focuses once again on Obamacare and Democratic Sen. Mark Udall’s broken promise that “if you like your health plan, you can keep it.”

“It’s time we have a new generation of leadership in the Senate that is focused on reforming our healthcare system for the next generation,” Gardner said in a release from his campaign.

“When our family’s healthcare plan was cancelled because of Obamacare last year, we felt firsthand the painful effects of Senator Udall’s support for Obamacare. Countless families have seen their premiums rise, lost access to their doctors, or lost their health insurances plans altogether — they have Senator Udall to thank.”

Holding what’s apparently the cancellation letter his family received, Gardner notes in the ad that “335,000 Coloradans had their plans cancelled too.”

Democrats have continually responded to Republicans’ use of that figure by noting that 92 percent of those who got cancellation letters were also offered renewal options that either complied with the Affordable Care Act’s coverage mandates or the option of keeping their existing non-ACA compliant plans.

Udall’s campaign responded Monday by blasting Gardner for voting dozens of times to repeal the Affordable Care Act.

“Congressman Gardner has voted 51 times to go back to a time when insurance companies could jack up your rates, cut your coverage, pocket your cash and then drop you if you got sick. Just like women’s health and immigration, Gardner’s views on health care are backwards and wrong,” said Udall for Colorado spokesperson Kristin Lynch.

“Coloradans want a senator like Mark Udall who is fighting to make the new health care law work for Colorado, not a partisan grandstander like Rep. Gardner who would let insurers discriminate against Coloradans with preexisting conditions.”

Colorado’s uninsured rate has dropped six points from 17 percent in 2013 to 11 percent this July, the fifth biggest drop of any state.

Last week, another ad from Crossroads GPS featured a Castle Rock woman attacking Udall for supporting Obamacare, which the ad claims forced her to go back to work.

The woman, Richelle McKim, told FOX31 Denver that she actually went back to work for reasons other than Obamacare, although she personally disagrees with the law’s individual mandate that all Americans be insured.