A year after voters turned out in record numbers to help Democrats recapture the House majority with health care -- not the Russia investigation -- as their top concern, Republicans refuse to address their worst political liability heading toward the 2020 elections.

Alarm bells are ringing in the deep-red South where Republicans have lost gubernatorial races this month in Kentucky and Louisiana -- despite rallies President Trump held to boost their prospects -- largely on the issue of Medicaid expansion. Republicans in Washington better hear them.

Andy Beshear upset incumbent Gov. Matt Bevin in Kentucky, campaigning against the work requirements Bevin put on Medicaid in a state that had seen the uninsured rate for adults too young for Medicare drop from 21% to 7%. Democratic Gov. Jon Bel Edwards fended off a GOP challenge Saturday from a candidate pledging to block new enrollment in Medicaid and conduct stricter oversight of how recipients qualify for benefits.

Kansas Gov. Laura Kelly, a Democrat, won her race in 2018 after running on the same issue in a state Trump won by 20 percentage points. Since then she has battled with Republicans in the state legislature who are pushing for work requirements she has called “a non-starter.”

“Medicaid is kryptonite to Republicans once it’s been introduced,” Matthew Continetti, founder of The Free Beacon and a conservative, noted on “Meet the Press” the week before Edwards prevailed. “In places like Kentucky, Louisiana where [expansion] has been introduced, Republicans have to come to grips with the fact that the safety net is not going anywhere.”

So while the issue threatens red-state Republicans, smart Democrats will campaign on Medicaid in purple states such as Florida, Wisconsin, Georgia, North Carolina and Texas, where it has not been expanded. If Democrat Doug Jones, the most vulnerable senator up for reelection next year, holds on to his seat in Alabama, it will likely be because of Medicaid expansion.

“Time and again, people in states across the country have affirmed their support for expansion by supporting candidates who embrace the Medicaid program,” said Democrat Capri S. Cafaro, executive in residence at American University’s School of Public Affairs, citing both the Kentucky governor’s race and elections in Utah and Nebraska, where the issue was explicitly on the ballot. “Medicaid expansion’s popularity amongst the electorate is growing and thus will remain a prominent policy issue in the 2020 election,” added the former minority leader in the Ohio Senate where she co-authored and co-sponsored a Medicaid reform law.

In addition to their anxieties over coverage and costs, GOP voters in rural areas are victims of a burgeoning hospital closure crisis. Since 2010 Texas has seen 17 hospitals close, for example. According to a report by the Urban Institute, nearly 20% of Texans younger than 65 are uninsured despite most of them working, the highest number in the country. There is majority support in the Lone Star State for expanding Medicaid, and health care will be a huge political burden for Republicans on the ballot there next year as Democrats work to replicate the turnout surge they saw in 2018. Sen. Ted Cruz, who won his race last year by only 2.6 percentage points, said while he thinks Sen. John Cornyn and President Trump can win next year, he admits it’s a state that “will be hotly contested.”

At the nearly 10-year anniversary of passing the Affordable Care Act, Democrats -- who were on defense over the law’s unpopularity during four elections in six years -- were on offense in the 2018 midterms touting the successes of Obamacare, a program that is now more popular than President Trump. In May, our RealClear Opinion Research poll showed health care remained the number one issue for voters at 36%, 10 points higher than the economy and more than 21 points ahead of immigration.

Earlier this year, Trump declared the GOP to be “the party of health care” and enthusiastically repeated that assertion, promising voters a plan was being developed that would produce “far lower” costs and would be “on full display during the Election as a much better & less expensive alternative to ObamaCare...”

That is not happening -- no one is developing a health care plan that Trump and Republicans will be campaigning on next year. What is happening is the administration has joined a lawsuit that may end up in the Supreme Court, and be decided next summer, that could dismantle the rest of Obamacare (the individual mandate was eliminated by the GOP tax law of 2017), rendering 20 million people uninsured and destabilizing the entire system. The administration has also issued new federal rules or executive orders on health care, but they are likely to face legal challenges and it’s unclear whether they will represent changes significant enough for voters to experience by next year’s elections.

Meanwhile, prospects for bipartisan drug pricing legislation are fading as the left demands something more perfect while the right says proposed price controls will threaten innovation. This will further frustrate voters who have paid an additional $5.1 billion more for the seven most-prescribed drugs in the last two years alone -- despite hearing Democrats and the president tout the issue as a top priority.

For all the criticisms Trump is spewing these days about the “Do Nothing Democrats,” it will be hard for him to attack them on health care. That’s because the GOP failed to repeal and replace health care before the 2018 midterm elections, and the party has ignored the issue ever since.

But Democrats can blow their advantage if they nominate Sens. Elizabeth Warren or Bernie Sanders, who both support Medicare for All. That plan is deeply unpopular with general election voters, swing state voters and most Democratic primary voters, who support a public option instead. The Republicans’ health care plan is to run against Medicare for All as a scary, costly and socialist plot to ruin health care as we know it. If Democrats oblige them, Republicans will be rescued from their decision to turn their backs on the voters’ number one concern.