The GOP has tried to turn other key Democratic arguments on their heads during the midterms. Democrats have argued that Republicans could try to trim Social Security, Medicare and Medicaid in order to make up for the lost revenue from their tax plan passed last year. The GOP, in turn, has contended that Democrats who propose a Medicare for All health-care plan could hurt seniors who rely on the government program.

President Donald Trump went even further at a rally Thursday night in Minnesota, which plays host to four competitive House races this year. He claimed without offering evidence that "some of the Democrats have been talking about ending pre-existing conditions." No Democratic candidates have proposed that.

Rohrabacher's sudden shift on health care fits in with a broader Republican strategy adopted as Democrats hammer GOP candidates over attempts to repeal Obamacare. Republican candidates across the country, even some state attorneys general who signed on to a lawsuit challenging pre-existing conditions coverage, are now promising to protect the insurance provisions.

Rohrabacher represents the 48th Congressional District, which runs along the Southern California coast from Seal Beach to Laguna Niguel. Republicans have a nearly 10 percentage point registration advantage in the district, but there have been changing demographics, and Democratic presidential candidate Hillary Clinton won the district by nearly 2 points in 2016.

California GOP Rep. Dana Rohrabacher, who is in a tight re-election race against Democratic challenger and businessman Harley Rouda, has gone personal with a new TV campaign commercial in which he discusses his daughter Annika's leukemia diagnosis and coverage for pre-existing health conditions. Yet the new ad doesn't talk about the Orange County politician's vote for the American Health Care Act of 2017. A Congressional Budget Office report warned the AHCA would result in 23 million Americans losing health-care coverage and would undermine protections for pre-existing medical conditions. "Politicians argue a lot about health care, but for me it's personal," Rohrabacher is heard saying in the 30-second ad . "When my daughter Annika was 8 years old she was afflicted with leukemia. It was devastating to my family, but we got through it — and today she's doing great." He adds, "So for her and all our families, we must protect America's health-care system. That's why I'm taking on both parties and fighting for those with pre-existing conditions."

While health care has been a key issue on the campaign trail, one California political analyst suggests Rohrabacher may have another reason for trying to change the focus: ties to the Kremlin that are not playing well in his district. Russia once viewed Rohrabacher as an intelligence source and gave him a code name, The New York Times reported last November.

"Congressman Rohrabacher is responding to the fact that he's at risk for several reasons," said veteran political analyst Sherry Bebitch Jeffe, a professor of the practice of public policy communication at the University of Southern California.



She added, "He wants to change the debate. He wants to change the focus from 'Putin's favorite congressman' to 'I'm one of you — and I'm with you' — and 'I'm not with the Republicans who want to take health care away.'"

Rohrabacher claimed once to have arm-wrestled with Vladimir Putin in the early 1990s, prior to Putin becoming the Russian president.

There have even been jokes among top House leaders about Rohrabacher's pro-Russia sympathies.



Back in mid-2016, House Majority Leader Kevin McCarthy, a fellow Californian, privately joked with colleagues: "There's two people, I think, Putin pays: Rohrabacher and Trump," according to The Washington Post.

With a month to go before the November election, Rohrabacher and Rouda are in a virtual tie, with each having 48 percent, according to a poll out Thursday that was conducted for the Los Angeles Times by the University of California at Berkeley's Institute of Governmental Studies. The poll found 10 percent of registered Republicans and 45 percent of undecided voters were less likely to vote for Rohrabacher because of his Russian ties.

"Dana Rohrabacher's latest campaign ad on pre-existing conditions is a bold-faced lie," said Jack d'Annibale, a spokesman for Rouda. He said Rohrabacher voted more than a dozen times to get rid of protections for pre-existing conditions under Obamacare, or the Affordable Care Act. He contends the congressman "misled constituents by proclaiming that the House GOP health plan supports protections for Americans with pre-existing conditions."



Dale Neugebauer, a spokesman for the Rohrabacher campaign, responded by emailing a link to a USA Today opinion piece the congressman wrote last year about his approach on covering pre-existing medical conditions. He also maintained that the congressman "has consistently supported protections for Americans with pre-existing conditions."



Rohrabacher once called Obamacare "disastrous." Rouda, meantime, has called Obamacare "a great program" and wants Medicare to be available for all residents.



The pre-existing conditions ad featuring Rohrabacher's daughter is running on cable and launched Saturday. His campaign said the ad marks his first general election ad.

The Rouda campaign ran an ad earlier this year that focused on Rohrabacher's connections to Putin, and several Democratic PACs also have run digital and other ads along the same lines. It includes Red to Blue California PAC's parody ad last month that features an image of Putin with a mock Russian Federation endorsement of Rohrabacher.



Rohrabacher has defended Russia's 2014 annexation of Ukraine's Crimea Peninsula. He also met in 2015 with Maria Butina, who this summer was arrested by the FBI and accused of being a Russian spy. Politico reported that he called the charge against her "bogus."

— CNBC's Jacob Pramuk contributed to this article.