The raucous welcomes and thundering applause that have greeted America’s newest (and oldest) political rock star, the septuagenarian Bernie Sanders, have launched a cottage industry of puzzled pundits trying to figure out the source of his appeal. Of course it’s his ideas, his supporters have insisted, perhaps as well as his presentation style, which issues from an agreeable set of features topped by undisciplined strands of white hair, giving him a sort of aged, professorial look of a speaker waving his arms while hurling his points across the lectern before the class ends.

So, what has he been proposing, as he continues to cleave chunks of supporters from Hillary Clinton’s troubled political base? Quite a few things, actually. He wants to centralize the current healthcare system even more than the Affordable Care Act did by having the federal government guarantee health care for all under a single-payer system. Social Security would receive a big increase, along with more funds for rebuilding roads, bridges, and airports, and significant amounts of taxpayer moneys to defray the expenses for “free” college attendance, paid family and medical leave, youth job initiatives, child care, and pre-K programs.

What is the price of all this over the next decade? A cool $18 trillion, which also would raise government spending from about 20 percent of the GDP to 30 percent in its first year of implementation, according to a Wall Street Journal analysis. No matter; Sanders continues to fill stadiums to overflowing, with cheering crowds clamoring for more, more, more. More “free” stuff, more security, more continuous peace of mind.

Which brings us to our main point, which is that there is something unsettling about all this, about the whole Sanders phenomenon, which has cast a spell on perhaps 20 percent of Democrats — not a small amount, by any means. And it simply is this: Sanders appeals to many of those who are quick to blame distant “evil-doers” for their difficulties — big banks, greedy corporations, bad billionaires, or the capitalist class as whole — while the politicians they have supported over the years get off with nary a soupcon of doubt. Further, Sanders’s enthusiastic supporters want everything immediately, regardless of the consequences, costs, the future, our children and grandchildren, or even America’s constitutional system.

I believe all of this distills to an approach toward life that literally can be best described as infantile. What is infantilism? Merriam-Webster defines it as “retention of childish physical, mental, or emotional qualities in adult life,” which admittedly is not too helpful. But in its political context, I think the meaning becomes clearer as one considers proclivities to shun responsibility, blame others, be obsessed with the present and abjure the future, avoid painful decisions, and, frankly, try to escape from any unpleasant reality. Indeed, anyone who has raised children and grandchildren is familiar with these characteristics. The political expression of an infantilized population is what for the past half century or so has been termed accurately as the nanny state.

To all this, of course, one could respond, so what? Perhaps America should become more like Europe, especially if enough of our citizens vote to move in that direction. The problem with this answer is that Europe has prospered from the military largess of America for so long, and Europeans have been so infantilized by their welfare states, that they no longer seem to have the will to live or to think much beyond the present. European birth rates, for instance, are so low that several countries on the continent are in a population death spiral.

Indeed, with their burgeoning Muslim citizens and refugees, countries such as Germany, France, and England are going to have to make serious existential decisions about defending their cultures, and more broadly, western civilization. And if Americans in larger numbers become more like Europeans, then who will defend the West against its adversaries?  Worse, who will defend America?

The answer is, certainly not those who have succumbed to the siren song of Bernie Sanders’s political infantilism. America’s progress as a great country depends on those capable of making hard decisions and taking responsibility for them. Whether enough grownups will remain to lead our country throughout the 21st century is the most important question Americans face. Indeed, we’ll learn much about the answer in next year’s election.