Republicans have a built-in contradiction at the core of their politics, and they’re not likely to resolve it any time soon. On the one hand, they really, really want to do something to reduce the cost and scope of the big middle-class “entitlement” programs, Social Security and Medicare — if only to generate more dollars for tax cuts and defense. It’s why their chief fiscal engineer, Paul Ryan, was an early supporter of Social Security partial privatization, and included a Medicare overhaul (replacing defined benefits with “premium support,” or vouchers) in all those Ryan budgets. But Republicans are also afraid to go after these programs because (aside from the fact that they are wildly popular) the chief beneficiaries are seniors, who are the most pro-GOP age group (in part because over-65 voters are whiter than younger age cohorts).

This is why Republicans desperately want bipartisan cover for “entitlement reform” (it was the foundation for all those Grand Bargain negotiations with Barack Obama not that long ago). And it’s also why whenever they can’t get Medicare cuts, they’ll turn on a dime and pose as the stout defenders of the program against Democratic efforts to raid it to give health-care benefits to other people. That’s exactly what we are seeing in new attacks by Donald Trump and Rick Scott, among others, on Medicare for All as a threat to — Medicare!

Here’s Trump on the stump trying this out:

It is true, as I have argued myself, that single-payer proposals flying under the flag of Medicare for All aren’t a simple extension of Medicare as it exists today to the general population. But for the most part, single-payer (at least in the proposals of Bernie Sanders and other leading Democrats) would be a more generous, not less generous, version of Medicare, as Jonathan Cohn notes:

[P]art of their plan is to make Medicare more generous, by eliminating the program’s high out-of-pocket costs that lead many seniors to buy supplemental so-called Medigap plans or to enroll in private alternatives. Sanders and his allies like to talk about “Medicare for all,” but a more accurate moniker for their plans would be “better Medicare for all.”

Yes, Medicare for All would shut down the privately run Medicare Advantage plans that about a third of Medicare beneficiaries choose, though as Cohn says, many do so because they offer enhanced benefits that the government would provide in single-payer systems — along with many more benefits such as dental and even long-term care that Medicare does not provide at all. At a fundamental level, Medicare for All would make the inherent socialism of traditional Medicare more systematic, and then make eligibility universal.

If Republicans were strictly attacking Medicare for All because of the tax increases it will most definitely require (though they’ll be more than offset, say proponents, by savings in private health-insurance premiums, out-of-pocket expenses, and coverage denials), that would be one thing. There are other vulnerabilities as well, such as the impact of single-payer on health-care providers, many of whom dislike Medicare as it exists today.