Bernie Sanders is a menace to the Democrats

Senator Bernie Sanders is a decent human being and a passionate politician. He is also a grave threat to the Democratic Party. Because the Democratic Party is currently the only major US party devoted to moderation and rational empiricism, Sanders's robust campaign for president is consequently a threat to the US as well.
The Republican Party has been debilitated, as a source of policies and as a governing party, by the ever more stringent ideological demands that the party's powerful and adamant fringe imposes on its diminished and enfeebled centre.
Sanders lacks the talent for sneering contempt that animates the candidacies of Ted Cruz, Chris Christie, Donald Trump and, often enough, Marco Rubio. But he shares other unwelcome attributes.
The American economy, a sprawling, $18 trillion behemoth stretching and contracting in more directions at once than anyone can possibly comprehend, much less control, is "rigged," Sanders says. This claim, too, owes much to a paranoid style. Who has rigged this giganotosaurus of disparate goods and endlessly varied services? Perhaps "Wall Street." Or maybe "corporations."
In politics, any force too spectral to wear a proper name is too elusive to be contained by government or law. Sanders all but admits as much. He posits that his election to the White House, where he would command the vast levers of the executive branch, would be insufficient to unrig things. A majority of electoral votes might suffice for a "moderate" like Hillary Clinton; Sanders, however, requires a "revolution."
In Thursday's MSNBC debate in New Hampshire, Sanders exposed other troubling signs reminiscent of some of his right-wing counterparts. His preoccupation with who is and is not a true "progressive" is the mirror image of the right-wing obsession with doctrinal purity and the tedious, narcissistic battle over who is a "true conservative" and who is a compromising RINO.
More surprising, Sanders exhibited a lazy contempt for the rigours of the job he seeks. Confronted with actual policy questions, Ben Carson and Donald Trump stumble in the darkness, knocking over lamps and bumping into unfamiliar furniture. They want to be president but can't be bothered to learn information essential to the job.
Sanders is no Carson or Trump; he lacks their preening self-regard (in the form of false humility in Carson's case) and their casual contempt for voters. But Sanders is almost exclusively animated by economic inequality and injustice. His lack of preparation and mental agility on foreign policy, apparent in the MSNBC debate, is alarming.
A president is the nation's commander in chief and lead diplomat. Sanders's failure to wrap his head around those responsibilities, nine months after he announced his bid for president, is inexcusable. "IS" is not the answer to every question about the Middle East. And there is more to foreign policy acumen than a vote against the Iraq War 14 years ago.
None of these problems is a hindrance to Sanders in the Senate, where he is one of 100. But Sanders is no longer content there. He is trying to build a movement to dominate the Democratic Party and go on to win the White House. Democrats can ill afford either outcome.
For more than two decades the GOP has veered deeper into disaster. Unable to adapt to the rapid cultural, technological, economic and global changes thrust upon it, the party has fomented backlash and reaction. The national Democratic Party, meanwhile, has left its 1970s dysfunction behind. Flexible and functional, it has displayed pragmatism (how much did Nancy Pelosi NOT want to bail out Wall Street in 2008?) and moderation (basing its health-care reform on the plan of a conservative think tank) and knowing, most of the time, more or less, when to take half, or quarter, of a policy loaf when the whole is unobtainable.
Sanders threatens that. Should he wrench a sizable part of the party in his direction, and keep it, Democrats risk resembling Republicans in all their sorry ideological fixations, infighting and incompetence. If a large, radicalised faction emerges on the Democratic side, as it has within the GOP, the nation could truly become ungovernable, paralysed by two fractured parties equally incapable of reconciling themselves to complex realities.
This is not the promise of Sanders's vision. But it is a potential consequence of it. Like others, Democrats have a lot of pent-up frustration. Many, no doubt, are eager to stick it to the man. But the man, and even the stick, are metaphors, and pretty shallow ones at that. The Democratic Party's hard-won successes -- on health care, climate, financial regulation and more -- are, by contrast, both real and profound. Which is the sturdier political foundation for a just future? - Bloomberg View