WASHINGTON—President Donald Trump is stepping up his attack on Democrats over a health care proposal called Medicare for All, claiming it “would end Medicare as we know it and take away benefits that seniors have paid for their entire lives.”

Trump, omitting any mention of improved benefits for seniors that Democrats promise, writes in an op-ed published Wednesday in USA Today, “The Democrats’ plan means that after a life of hard work and sacrifice, seniors would no longer be able to depend on the benefits they were promised.”

But Medicare for All means different things to different Democrats. The plan pushed by Sen. Bernie Sanders, the Vermont independent who challenged Hillary Clinton for the 2016 Democratic presidential nomination, would expand Medicare to cover almost everyone in the country, and current Medicare recipients would get improved benefits. Other Democratic plans would allow people to buy into a new government system modeled on Medicare, moving toward the goal of coverage for all while leaving private insurance in place.

Trump’s column comes as he is looking to paint Democratic candidates as extreme ahead of next month’s midterm elections. A White House official speaking to The Associated Press on the condition of anonymity to describe internal plans said that Trump’s health care attack will be echoed by the Republican National Committee and other GOP groups and that the president will continue to raise the attack during his campaign rallies.

As Trump escalates his efforts on behalf of fellow Republicans, he is casting health care as one of an expanding list of choices for the electorate this year while seeking to raise the alarm about the consequences of Democratic control of the House or the Senate.

Medicare for All, also called single-payer over the years, was until fairly recently outside the mainstream of Democratic politics, but this year it has become a key litmus test in many party primaries and a rallying cry for progressive candidates. Under the plan by Sanders, all Americans would gain access to government insurance with no copays or deductibles for medical services.

Republicans contend that the proposal would be cost-prohibitive and argue it marks government overreach.

Trump has already sought to paint Democrats as extremists after the bitter confirmation battle over Supreme Court Justice Brett Kavanaugh, and internal GOP polling obtained last month by the AP shows that the party believes the message will help galvanize Republican voters to the polls.

At a rally in Iowa on Tuesday, Trump argued that the only reason to vote for Democrats “is if you are tired of winning.” He will be holding a rally in Pennsylvania on Wednesday evening.