Leah Millis / Reuters

Here’s an amazing political statistic: In 2016, the Affordable Care Act came up in just 10 percent of pro-Democrat campaign advertisements and 16 percent of pro-Republican ones. This year, it came up in more than half of Democratic ads and nearly a third of those for Republicans.

Those numbers, which come from the Wesleyan Media Project, help demonstrate the way the law’s politics have gone topsy-turvy and its political sway has grown since President Donald Trump came into office. After 2016, Republicans found themselves in the position of fighting against a law that suddenly went from being unpopular to being popular. And Democrats found themselves in the position of fighting to defend its good parts rather than having to explain away its bad ones. For the first time in nearly a decade, they’re running on health care rather than away from it.

Health care has become the single most important policy topic in the midterm elections—everywhere and nowhere, a strange kind of omnipresent sleeper issue. It’s not grabbing many national headlines, compared with the migrant caravan or the Supreme Court fight or violence directed against minority groups or the trade war, but it’s motivating voters in race after race after race. New polling from the Public Religion Research Institute shows that Americans point to the cost of health care more than any other issue when asked what is most important to them this election cycle. “It’s official: The 2018 midterms are about health care,” Wesleyan argued.

With good reason. There’s policy at stake. Ballot initiatives in three very red states—Utah, Nebraska, and Idaho—are seeking to expand Medicaid coverage to more than 300,000 people. “What we’re seeing is that health care doesn’t have to be partisan,” said Jonathan Schleifer, the executive director of the Fairness Project, an advocacy group that has supported the initiatives. “The Medicaid expansion has enormous bipartisan appeal because it’s the compassionate thing to do and the fiscally responsible thing to do.” In Washington, Republicans continue to stand queasily behind their own vaporware-type plans to repeal the ACA and replace it with something smaller and worse, while at the same time chipping away at coverage through regulatory provisions and the courts.

The status quo remains fraught, too. Though the rate of American adults without insurance has dropped from 18.2 percent when the ACA passed to 10.3 percent as of 2016, nearly 30 million mostly lower-income people still lack coverage, putting their health at risk and leaving them vulnerable to bankruptcy as a result of a car accident or sudden illness. Moreover, the cost of coverage and care remains a heavy burden for millions of families, with the growth of out-of-pocket costs continuing to outstrip the growth in wages. “The debate is about this amorphous thing called ‘health care,’” said Drew Altman, the president of the Henry J. Kaiser Family Foundation. “The big crisis in health care now is a crisis of out-of-pocket costs for people who are sick.”

For Democrats, the pitch to those voters is straightforward: We are the party that will shore up the Affordable Care Act, maintain protections for preexisting conditions, and work to make coverage universal and affordable. For the first time in years, the party is defending a popular law rather than an unpopular one—and is doing so vocally, playing on voters’ very real fears that Republicans will take away their coverage. In Missouri, Senator Claire McCaskill is on a “Your Health Care, Your Vote” tour. In West Virginia, Senator Joe Manchin is pressing on health care, too, cutting an ad in which he blasts the lawsuit that would take away coverage for preexisting conditions with a shotgun.

For Republicans, the law’s sudden popularity—and their continual efforts to reduce coverage and increase costs—have made their campaign pitch a little harder. With no real health plan to run on, many have alighted on the bizarre argument that they would protect individuals with preexisting conditions. “The president’s health-care plan,” Sarah Sanders, the White House press secretary, told reporters last month, “covers preexisting conditions.” (That health plan does not exist in any real form.) Senator Dean Heller of Nevada, Senator Ted Cruz of Texas, Wisconsin Governor Scott Walker, and California Representative Dana Rohrabacher, among others, have gotten caught on both sides of the issue.

A more coherent if more fanciful Republican argument goes after Medicare for All, the Democrats’ long-term promise of providing universal public coverage. “They want to raid Medicare to pay for socialism,” Trump said at a rally in Indiana in August. Florida Governor Rick Scott, among other conservatives, has picked up the attack line. (So has the program’s federal administrator, Seema Verma, tweeting this week, “Medicare for All isn’t a joke. It’s a multi-trillion dollar drain on the American economy that will bankrupt future generations.”) But Democrats would need control of the House, Senate, and White House to turn that campaign slogan into policy reality—and at the same time, Republican leaders in Congress are promising to take another run at shrinking Medicaid and gutting Medicare.

With Trump in the White House and voters focused on the health-policy details, Democrats are running for something popular and against something unpopular. Republicans have no popular plan of their own, their proposals on the issue are unpopular, and they are grasping for something to run against. And Americans are voting.

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