Sanders' candidacy can trace it roots back to the 19th-century populist party of Mary Elizabeth Lease who declaimed:
"Wall Street owns the country. It is no longer a government of the people, by the people, and for the people, but a government of Wall Street, by Wall Street, and for Wall Street. The great common people of this country are slaves, and monopoly is the master."
"Raise less corn and more hell!" Mary admonished the farmers of Kansas.
William Jennings Bryan captured the Democratic nomination in 1896 by denouncing the gold standard beloved of the hard money men of his day: "You shall not press down upon the brow of labor this crown of thorns, you shall not crucify mankind upon a cross of gold."
Sanders is in that tradition, if not in that league as an orator. His followers, largely white, $50,000-a-year folks with college degrees, call to mind more the followers of George McGovern than Jennings Bryan.
Yet the stagnation of workers' wages as the billionaire boys club admits new members, and the hemorrhaging of U.S. jobs under trade deals done for the Davos-Doha crowd, has created a blazing issue of economic inequality that propels the Sanders campaign.
Between his issues and Trump's there is overlap. Both denounce the trade deals that deindustrialized America and shipped millions of jobs off to Mexico, Asia and China. But Trump has connected to an even more powerful current.
That is the issue of uncontrolled and illegal immigration, the sense America's borders are undefended, that untold millions of lawbreakers are in our country, and more are coming. While most come to work, they are taking American jobs and consuming tax dollars, and too many come to rob, rape, murder and make a living selling drugs.
Moreover, the politicians who have talked about this for decades are a pack of phonies who have done little to secure the border.
Trump boasts that he will get the job done, as he gets done all other jobs he has undertaken. And his poll ratings are one measure of how far out of touch the Republican establishment is with the Republican heartland.
When Trump ridicules his rivals as Lilliputians and mocks the celebrity media, the Republican base cheers and laughs with him.
He is boastful, brash, defiant, unapologetic, loves campaigning, and is putting on a great show with his Trump planes and 100-foot-long stretch limos. "Every man a king but no man wears a crown," said Huey Long. "I'm gonna make America great again," says Donald.
Compared to Trump, all the other candidates, including Hillary Clinton and Jeb Bush, are boring. He makes politics entertaining, fun.
Trump also benefits from the perception that his rivals and the press want him out of the race and are desperately seizing upon any gaffe to drive him out. The piling on, the abandonment of Trump by the corporate elite, may have cost him a lot of money. But it also brought him support he would not otherwise have had.
For no group of Americans has been called more names than the base of the GOP. The attacks that caused the establishment to wash its hands of Trump as an embarrassment brought the base to his defense.
But can Trump win?
If his poll numbers hold, Trump will be there six months from now when the Sweet 16 is cut to the Final Four, and he will likely be in the finals. For if Trump is running at 18 or 20 percent nationally then, among Republicans, it is hard to see how two rivals beat him.
For Trump not to be in the hunt as the New Hampshire primary opens, his campaign will have to implode, as Gary Hart's did in 1987, and Bill Clinton's almost did in 1992.
Thus, in the next six months, Trump will have to commit some truly egregious blunder that costs him his present following. Or the dirt divers of the media and "oppo research" arms of the other campaigns will have to come up with some high-yield IEDs.
Presidential primaries are minefields for the incautious, and Trump is not a cautious man. And it is difficult to see how, in a two-man race against the favorite of the Republican establishment, he could win enough primaries, caucuses and delegates to capture 50 percent of the convention votes.
For almost all of the candidates who will have dropped out by then will have endorsed the last man standing against Trump. And should Trump be nominated, his candidacy would make Barry Goldwater look like the great uniter of the GOP.
Still, who expected Donald Trump to be in the catbird seat in the GOP nomination run before the first presidential debate? And even his TV antagonists cannot deny he has been great for ratings.