As President Donald Trump talked up his plans to deploy 15,000 troops to confront a "national emergency'' at the Mexican border, Democratic activist Amber Pallante walked through a Burlington County neighborhood late last month, worried about the closer-to-home threat of losing health insurance.

"I care about what there is going to be for my kids,'' said Pallante, a canvasser for Andy Kim, the Democratic candidate for the 3rd Congressional District, who moments earlier engaged in a polite but slow-burn debate with a Trump supporter.

"Are they going to be able to find a full-time job? Are they ever going to get medical care?" she asked. "I don't know."

Trump is closing out the bitter 2018 midterm contest with an ominous, obsessional focus on immigration.

His pledge to send troops to confront a slow-moving caravan of Central American migrants and his pledge to end birthright citizenship with an executive order are widely seen as a desperate, last-minute attempt to energize his base in the face of a Democratic wave.

Yet poll after poll in New Jersey has said that concerns over health care far outweigh worries about the economy, ethics and other issues, including immigration. In fact, health care has been a top voter priority for more than a decade, and most dramatically in 2010, with a Tea Party-fueled backlash over the Affordable Care Act, President Barack Obama's signature health care law.

Right-wing critics called the Affordable Care Act socialized medicine that threatened the very fabric of democracy. They warned that "Obamacare" would destroy the economy. The campaign of fury worked. Democrats lost 63 House seats and majority control that year in Obama's 2010 midterms — a "shellacking," he called it.

And Republicans vowed to repeal and replace the law.

Republicans shift gears

Now the tide has turned.

The GOP-controlled Congress slammed into a new political reality last year when it attempted — and failed — to fulfill the vow, despite Trump's prodding.

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They discovered that the public cherishes some of the law's consumer protections, such as requiring companies to offer insurance to people with prior illnesses, like cancer, diabetes or cystic fibrosis, and extending coverage to children up to the age of 26. Medicaid, which was expanded under the law, offered health care to millions of low-income families and drug treatment to millions struggling with opioid addiction.

In addition, a January 2017 Pew Research survey said 60 percent of Americans believe that government should be responsible for insuring health care, a 9-point jump from the previous year and the highest number in nearly a decade.

“It isn’t that people fell in love with the ACA — with the exchanges and mandates and controlled benefits and everything — they didn’t,” Robert J. Blendon, a professor of health policy and political analysis at Harvard University told USA Today earlier this year. “They just couldn’t imagine taking some coverage away from those people."

That sentiment helps explain why some Republicans, including Trump, have quickly become converts, vowing to protect popular components of the law.

Yet the credibility of the GOP's conversion is undermined by Trump's own disdain for Obamacare.

Frustrated with the GOP's inability to deliver on its decade-long promise to dismantle the law, Trump took a meat ax to it. He issued executive orders easing the law's regulations, cut funding that promoted enrollment, and signed a tax overhaul that also stripped the law's mandate requiring that a majority of Americans buy health insurance.

And, in a move that has become a rallying point for Democratic candidates, Trump's Justice Department in June filed a lawsuit in Texas seeking to strike down core provisions, including requirement to cover people with prior illnesses.

Menendez and Democrats take aim

"It's amazing that while I hear [Republican] colleagues and others talking about wanting to eliminate pre-existing condition discrimination ... the administration is arguing in a federal court that the entire law is unconstitutional,'' said Sen. Bob Menendez, the Paramus Democrat who is facing a fierce challenge from Republican Bob Hugin, a former pharmaceutical company executive.

On the campaign trail, Democrats have welded Trump to the hip of their GOP opponents. Democratic candidates are vowing to fix the law but warn that maintaining a GOP-controlled Congress would mean the law's certain doom. It's a case they make with emotional appeals and hard-boiled attacks.

Tom MacArthur, the 3rd District incumbent who is seeking his third term, has the biggest bull's-eye on his back because of his role last year in brokering a compromise that led to the repeal and replacement bill — the American Health Care Act of 2017 — passing the House by just one vote. The effort ultimately failed in the Senate, but it has come back to haunt MacArthur on the trail.

"These people are angry. Why? because MacArthur is the chief architect behind jeopardizing health coverage for people with pre-existing medical conditions,'' says the narrator of a 30-second ad that includes footage of a town hall last year where MacArthur was confronted by angry residents. The House Majority PAC, which is closely aligned with House Minority Leader Nancy Pelosi, paid for the ad.

MacArthur says his amendment prohibited states from denying anyone insurance because of a pre-existing condition, but critics and analysts said the language was largely meaningless since the law would have given insurance companies far more leeway to raise prices and thus make insurance unaffordable for many with long-standing health issues.

MacArthur notes that the bill also would have created a $138 billion fund for high-risk pools to help defray costs for sick people who might otherwise find insurance too expensive. But critics and health care analysts said the pool was insufficient.

The attack ad also claims that the GOP bill he supported puts an "age tax" on older Americans. But there was no such tax in the bill.

That phrase is an attack slogan crafted by the American Association for Retired Persons, which lobbied against MacArthur's amendment. It refers to a provision that would have led to steep premium increases on people ages 50 to 64.

Yet the hikes would not affect veterans or people on Medicare, and MacArthur's amendment also included $90 billion in tax credits for those hit with the steep hikes.

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One of MacArthur's aides said the ad is misleading and frightening voters. Frank Luna, a MacArthur spokesman, recalled seeing an elderly woman approach MacArthur at a private home event in Berkeley Township, quivering as she asked, "Why have you voted to tax Medicare?" Luna said.

Other Democrats have also taken up the "age tax" cudgel, including Mikie Sherrill, the former U.S. Navy helicopter pilot and federal prosecutor vying to succeed veteran 11th Congressional District Republican Rodney Frelinghuysen, who is stepping down in January. She is facing Jay Webber, a Republican state lawmaker from Morris Plains.

Pre-existing conditions is focus

But Sherrill is relying on personal testimonies, including one from a Denville couple worrying about the long-term health care needs of their 2-year-old daughter, Josie, who was born with heart and lymphatic system complications.

"If policies changed around pre-existing conditions, that would threaten my daughter's physical well-being, her very life,'' the father, Scott, says in a video clip that the Sherrill campaign is posting on social media.

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Seeking to inoculate themselves against the Democratic attacks, Republicans are vowing to protect popular Affordable Care Act provisions, such as the pre-existing condition requirement, yet offering few details on how.

Sherrill has attacked Webber as opposing coverage for pre-existing provisions and cited votes he cast in the Legislature.

During a televised debate, Webber called the charge "baseless'' and vowed to support the mandate. Yet, in outlining plans to lower costs, Webber offered a rehash of GOP talking points, such as allowing people to seek coverage across state lines and limiting malpractice lawsuits.

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Hugin hit the airwaves last week casting himself as a pro-choice independent who will "protect patients with pre-existing conditions." It was a calculated attempt to distance himself from Trump, whom Hugin supported during the 2016 campaign. He was a delegate to the Republican National Convention and headed Trump's fundraising in New Jersey.

Menendez, whom Hugin has hammered relentlessly as corrupt and inept in a barrage of television ads, is closing the race with an ad reminding voters of Hugin's Trump ties.

"Hugin stood by Trump when he attacked Obamacare,'' the narrator says.

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But Ralph Hendrickson, 77, a retired principal from Burlington County, pretty much had his mind made up weeks before the two ads hit the airwaves.

"I'm concerned about people with pre-existing conditions, and I'm not so sure that Hugin will be where I want my senator to be with respect to that issue and generally for health coverage for all people,'' he said.