President Trump lies so frequently that, as the cliche goes, if he says the sky is blue, it’s best to look out your window and confirm that fact. Glenn Kessler of The Post’s Fact Checker says Trump has averaged 8.3 lies per day since taking office. So it’s saying something that, even by Trumpian standards, the president’s op-ed in Wednesday’s USA Today attacking Medicare-for-all and claiming he’ll defend Medicare from the Democrats sets a new standard for mendacity. As Kessler himself points out, Trump’s op-ed is one where “almost every sentence contained a misleading statement or falsehood.”

There’s a reason Trump and the Republican Party pose as the protectors of Medicare: Lies are all they’ve got. If anything, they are furiously trying to cut the legs out from under the program – and hoping you don’t notice.

In the USA Today piece, Trump acts as if there is only one Medicare expansion proposal on offer. False. There is everything from Bernie Sanders’ Medicare-for-all, which would set up a single-payer system, to various options that would allow people under the age of 65 ways to access the program. Trump claims — seemingly out of nowhere — it would “lead to the massive rationing of health care.” In fact, the Medicare-for-all bill introduced by Sen. Bernie Sanders (I-Vt.) would increase the program’s offerings, expanding it to cover everything from hearing aids to vision care — things that are currently not offered. And we have rationing of health care for everyone now, but that is what’s known as a wallet biopsy: More than 40 percent of Americans are forced to “ration” care because of cost.

Beyond the “rationing” myth, Trump claims he’s protecting coverage for Americans with preexisting conditions. In reality, his Justice Department is refusing to defend them in a current Texas court case. And tying it all together? A claim that this is all because of the socialist boogeyman. “If Democrats win control of Congress this November, we will come dangerously closer to socialism in America. Government-run health care is just the beginning,” he wrote.

Note to all: Medicare is government-run health care. I hear people like it! They like it so much, polls show as much as 70 percent of the population thinks Medicare-for-all is a great idea. Seniors seem to support it as much as anyone else — a Kaiser Health Tracking poll from earlier this year found a majority of people — including a majority of seniors — said they favored “a national health care plan, or Medicare-for-all.”

Health care, in fact, is shaping up to be the defining issue of next month’s midterm elections. Little wonder, then, that Democrats are on the offensive. Surveys show that no matter what the other cause of the week is, concerns about paying their hospital and other medical bills is on top of almost everyone’s list. At the same time, the Republican attempt to knock out preexisting condition protections has been far from popular — so much so that some Republicans, such as Trump, are actually now claiming they won’t do away with it, despite supporting health-care reform proposals or court actions that would undercut their own promise.

While Trump claims “Republicans want to protect Medicare,” his minions assure everyone he doesn’t mean it. Larry Kudlow, the president’s national economic council director, told an audience of corporate titans last month that the Trump administration would look to cut “larger entitlements” in 2019. Entitlements, if you don’t know, is Washington speak for Social Security and Medicare. Even as Trump vowed on the campaign trail that he wouldn’t touch Social Security and Medicare, his staff has undercut him. And it’s House Republicans who pushed a budget package that would cut Medicare by $537 billion over the next decade. And it’s House Speaker Paul D. Ryan (R-Wis.) who is attempting to push seniors off traditional Medicare and into the private marketplace by setting up “Medicare Exchanges.” These exchanges would function similarly to the Affordable Care Act — complete with subsidies based on income and the cost of the plans.

In fact, Trump is hardly the only myth-peddler when it comes to Medicare-for-all. This past summer, Seema Verma, the administrator of the Centers for Medicare and Medicaid Services, which operates the programs, told a San Francisco gathering, “Ideas like ‘Medicare for all’ would only serve to hurt and divert focus from seniors.” Longtime conservative health-care activist Betsy McCaughey recently claimed that under the Affordable Care Act, health care would be rationed with the result that seniors would be “pushed to the back of the line.” And Florida Gov. Rick Scott (R) opined “If you want to protect Medicare, vote Republican. If you want a socialist experiment with Medicare, by all means vote Democrat.” Let’s hope voters won’t let Trump and the GOP get away with this scam.