If you're searching for a unified theory to explain Donald Trump's victory, you search in vain. Like most such events, it is explainable only as the result of an unlikely sequence of circumstances, every single one of which had to come true to produce the final outcome.

In this particular case, the necessary sequence goes all the way back to 1789, to the founders' fateful decision to select presidents through the Electoral College rather than the popular vote. Little did they know what consequences that would produce. From there, the sequence runs all the way up through Bill Clinton's presidency and NAFTA, to Russia's intervention and the last-minute bungling by the FBI's James Comey, concluding with the simple failure of liberal voters to show up and vote in the right states.

All of those things had to happen, and then did happen, to produce President-elect Trump.

It would take a long, long time to sift through the historic implications of all that, and given all that's happening we don't have that luxury.  But we do know this much: From the Democrats' point of view, the election never should have been close enough to be settled by such outlandish twists of fate in the first place.

In hindsight, one of the circumstances necessary for a Trump victory was probably the nomination of Hillary Clinton. Four years ago, Democrats wanted to run a campaign in which they cast the Republicans as defenders of the elite and the wealthy 1 percent. When the Republicans nominated Mitt Romney, the walking, talking epitome of the wealthy elite, the Obama campaign could not have been more pleased. It's a rare gift to see your campaign's entire argument personified in your opponent.

Well, in 2016, the Democrats fully returned the favor.  Trump's campaign strategy was to rant and rail against the failings of the entrenched establishment, casting himself as the man who could come in and topple it, and in Clinton he was handed the perfect foil for that argument. Her ties to Wall Street, her six-figure speaking fees, the Clinton Foundation, her three decades in Washington, her status as former first lady, U.S. senator and secretary of state -- she came pre-packaged as a caricature of all that Trump wanted to talk about, and he took full advantage.

A lot of the Trump campaign against Clinton was based on lies. On the other hand, the problem with the description above is that it was largely true, and thus hard to refute

Would Bernie Sanders have done better? I doubt it. He may have had the right argument but he wasn't the right candidate. Elizabeth Warren would have been effective, but she didn't believe herself ready. And frankly, Obama and the Clintons have been such dominating figures over the last quarter-century that they have made it difficult for the party to raise a new crop of presidential-ready contenders. Now that the big oaks have fallen, sunlight should begin to hit the forest floor again.

But the Sanders example does raise an important question: How and why did the Democrats so quickly cede the economic argument that they had used effectively just four years earlier, and that Sanders had ridden to unlikely success in the primaries? Back in late spring and early summer, you may recall, the Clinton campaign was claiming to have learned a lot from Sanders' example, yet by the time fall rolled around, they seemed to abandon economic populism as a theme.

In one sense that was understandable, because Trump's obvious character failings and outrageous behavior offered an easy target in campaign ads and debates. In hindsight, they also proved a fatal distraction. The Clinton campaign chased the shiny objects that Trump always leaves in his wake and never aggressively prosecuted the economic fairness argument that might have made this a runaway.

Consider the huge natural advantages that the Democrats enjoyed yet threw away. According to Gallup, 61 percent of American voters believe that the wealthy pay too little in taxes; just 15 percent say they pay too much.  Sixty-seven percent believe corporations pay too little; just 12 percent believe they pay too much. Those sentiments are shared widely even within the GOP base.

Now contrast that with the Trump tax plan. According to the Tax Policy Center, the wealthiest 1 percent of taxpayers would enjoy more than 50 percent of the tax benefits under Trump's plan. The top 0.1 percent -- those with incomes of more than $3.7 million -- would enjoy an average tax cut of more than $1 million, for a 14 percent increase of their after-tax income, while middle-class households making $48,400 to $83,300 would see tax cuts of roughly $1,000, or a meager 1.8 percent increase in their after-tax income.

Put another way, the rich would get the lion's share, gorging themselves and leaving everybody else to squabble over what remained of the carcass.

The result is more than a little maddening. Over the next few months, we're going to watch a political party that ran on an anti-elitist message, a party elected on the notion that the establishment and special interests enjoy too many advantages, begin to enact policies that will consciously, deliberately compound those existing advantages. Then, having slashed government revenue, they will announce that a whole range of government programs have become unaffordable and will have to be slashed, again at the expense of the very people they were supposedly elected to help.

And the Democrats will bear a substantial part of the blame for that. They failed to offer voters a candidate and a message that would make clear the real stakes in this election. They became so caught up in talking about the things that were important to themselves and to their own base that they stopped talking about equally important things important to other voters.

Republicans would explain that failure by claiming that the Democrats just lost interest in those voters. I think there's something to that.