Is the Democratic Party becoming a mirror image of Donald Trump's Republican Party? Galloping leftist "extremism" — helped along by the populist rhetoric of Bernie Sanders and Alexandria Ocasio-Cortez — has centrists and conservatives fainting like myotonic goats at a fireworks show, from Dana Milbank at The Washington Post to former George W. Bush speechwriter Peter Wehner at The Atlantic.

However, Wehner's alarmist article inadvertently demonstrates the problem with this kind of panic-mongering — a lack of real consideration whether Sanders might be right about anything, or whether his politics fit at all with America's previous traditions. In reality, the growing Sanders tendency in the party mostly reflects it coming to its senses.

"To more fully grasp the leftward lurch of the Democratic Party," writes Wehner, his glasses steaming up in outrage, he runs through a list of Sanders-style policies. He asserts they would be "fiscally ruinous, invest massive and unwarranted trust in central planners, and weaken America's security."

First up is the Green New Deal. After describing it at least somewhat fairly as an effort to de-carbonize the economy as fast as possible while making it more egalitarian, he writes: "It would be astronomically costly and constitute by far the greatest centralization of power in American history." That's the sum total of his argument against it.

As usual for self-style moderates, Wehner does not even attempt to grapple with the threat posed by climate change, nor consider how much might be worth paying to stop it. The cost of a Green New Deal would be large, but so would letting half of south Florida drown. Freaking out about cost when facing clockwork costly climate disasters is an elementary failure of reasoning.

Meanwhile, describing a Green New Deal as an unprecedented centralization of power is historically illiterate. During the Second World War, the government routinely nationalized whole industries, conducted economy-wide price controls and rationing, and, you know, conscripted millions of men into the military to fight and die. The Green New Deal would involve some flexing of government power to be sure, but probably not even on the scale of the original New Deal. For instance, at its height in the mid-1930s, the Public Works Administration alone was consuming half the concrete output and one-third of the steel output of the entire country. The Green New Deal would have to be very big, but probably not that big.

In sum, Sanders is building on a cherished Democratic Party tradition (whose construction projects are still being used to this day across the country) to address a critical policy emergency. Scared yet??

Next up is Medicare-for-all, which Wehner asserts would be unpopular because of an insurance industry study showing 70 percent of people on employer-sponsored insurance are happy with it, and because the plan "would exacerbate the worst efficiencies of an already highly inefficient program."

This first point is deceptive, and the second is straight-up backwards. It's true that, per Gallup, 69 percent of people with employer-based coverage do say they are satisfied with it — but 77 percent of people on Medicare say the same thing. (Seniors aren't generally thrown into a panic when they turn 65 and get pretty good guaranteed coverage for the rest of their life.)

As for efficiency, the fragmented and heavily employer-based American insurance system is already by far the most wasteful in the world. Relative to the second-most expensive country, Switzerland, we spend about 5 points of GDP extra — or a trillion bucks, every year. Medicare is considerably more efficient than private coverage, with lower prices and much lower administrative spending. With some reforms — particularly allowing negotiation with drug companies — it could be more efficient still. Wehner simply doesn't know what he's talking about.

So Sanders understands correctly that the janky employer-based health care system is slowly crushing the economy and proposes building on one of the greatest successes of President Lyndon Johnson to fix it. Everyone hide under the bed!!

Taking on every one of Wehner's points would require several articles, but just one more thing: He complains that Sanders Democrats are showing "Increasing antipathy aimed at Israel, one of the most estimable nations in the world." Why the most high-profile Jew in American politics might question unswerving obedience to a corrupt government, aligned with violent racists, which works hand-in-glove with Democrats' partisan opponents, is left as an exercise for the reader.

To be sure, a President Bernie Sanders would probably be the furthest-left president in history, surpassing Franklin Roosevelt by a bit. But FDR was also the best president in history — unlike Wehner, a man who recognized that large problems like economic depression and global war against fascism require large solutions. Indeed, in some areas Sanders is to his right — his proposed 70 percent top marginal tax rate is far short of FDR's 94 percent rate (much less the maximum income he tried to pass), and bites in at a much higher income.

As such, Sanders is squarely within the reformist-radical American tradition — someone who wants to build on previous accomplishments to make the United States a more decent and equal society. It's as simple as that.