Can a septuagenarian socialist who just survived a heart attack and would be 80 years old in his first year in office be elected president of the United States? It's hard to believe but not impossible.
As of today, Bernie Sanders looks like one of the better, if not best, bets for the nomination. Polls have him running first or second in the first three contests: Iowa on Monday, and then New Hampshire and Nevada.
If Bernie can best main rival Joe Biden in Iowa, he will likely thump Joe in New Hampshire. Biden's campaign, built around "electability," could suffer a credibility collapse before he reaches South Carolina, where Joe is banking on his African American base to rescue him if necessary and give him a send-off victory straight into Super Tuesday.
If Sanders can beat Biden two or three times in the first four primaries in February, the last remaining roadblock on Sanders' path to the nomination could be Mike Bloomberg's billions.
Hillary Clinton may sneer, "Nobody likes him," but Bernie has a large, dedicated, loyal following, especially among millennials, and tens of thousands more small-dollar donors than any other Democratic candidate.
He is flush with cash. He has a radical agenda that appeals to the ideological left and the idealistic young. The rising star of the party, Alexandria Ocasio-Cortez, is campaigning alongside him.
And, say what you will, Sanders is no trimmer or time-server. He has consistently voted his values and views. He voted no to Bush 41's Gulf War, no to Bush 43's Iraq War, no to NAFTA, no to GATT. In the '80s, when President Reagan battled the Marxist Sandinistas in Nicaragua, Sanders was on the other side.
But what makes Sanders an appealing candidate for the Democratic nomination may prove poisonous to him as a party nominee in the fall.
For what does Bernie promise?
Free tuition at public colleges and forgiveness of all student debt. "Medicare for All," a single-payer government-run health care system that would require a huge hike in middle-class taxes and abolish private health insurance for the 160 million Americans currently enrolled.
He would break up the big banks, go after Wall Street, add $60 trillion of federal spending in the next decade, and raise income, corporate, capital gains, estate and inheritance taxes.
He would expand the government's share of the U.S. economy to levels rivaling that of France, the highest in the free world.
Bernie was first to back the Green New Deal and pledges to reach carbon neutrality in 10 years in energy and transportation. As for our oil, gas and coal producers, says Sanders, they "have evaded taxes, desecrated tribal lands, exploited workers and poisoned communities."
How would Sanders deal with the millions of illegal migrants now within the country? He'd welcome them all in.
Bernie has proposed the abolition of Immigration and Customs Enforcement and Customs and Border Protection and wants to provide a pathway to citizenship for the 11 million to 22 million illegal migrants already here. He would decriminalize border-jumping and give health and welfare benefits to the invaders.
He would decriminalize the breaching of America's borders.
"My first executive orders," tweeted Bernie last week, "will be to reverse every single thing President Trump has done to demonize and harm immigrants, including his racist and disgusting Muslim ban."
Leaders of the center-left think tank Third Way warn that a Sanders nomination risks a Democratic rout of the magnitude of the 49-state losses of George McGovern in 1972 and of Walter Mondale in 1984.
Vulnerable Democrats in moderate and swing districts would have to jump ship, abandoning the ticket to survive the slaughter.
Fearful of such an outcome to a Sanders-Trump race, super PACs run by moderate Democrats have begun to dump hundreds of thousands of dollars into attack ads to blunt his momentum in Iowa.
What Socialist Jeremy Corbyn did to Britain's Labour party -- leading it to the worst defeat since the 1930s -- Sanders could do to the Democratic Party, write Jon Cowan and Jim Kessler of Third Way.
In 2016, Sanders ran a surprisingly strong race for the nomination, and it was later learned that a supposedly neutral DNC had been in the tank for Hillary Clinton. The Democratic establishment, the party elite, had collaborated to put the fix in against Bernie.
Yet Sanders supported Clinton that fall. If, however, Bernie's last chance at the nomination is aborted by an establishment piling on, party super PACs running attack ads against him, and major media taking time out from trashing Trump to break Sanders, the Democratic Party will have the devil's time of it bringing Bernie's backers home in the fall.
Bernie's believers might just conclude that the real obstacle to their dream of remaking America is neither the radical right nor Donald Trump, but the elites within their own party.
Patrick J. Buchanan is the author of "Nixon's White House Wars: The Battles That Made and Broke a President and Divided America Forever."