If the Republican primary campaign sometimes resembles a farcical reenactment of Gulliver's Travels, with six-inch Lilliputians struggling (and failing) to subdue an unruly giant in their midst, the Democrats seem intent on updating the story of David and Goliath for the 21st century.

From the beginning, Hillary Clinton has been the clear Democratic frontrunner, with every possible advantage. And yet, Bernie Sanders has kept after her, making her fight for almost every state. It's always been unlikely he could take her down, and that remains true today. But his massive upset victory in Tuesday's Michigan primary has raised (for what feels like the umpteenth time) the question of Clinton's vulnerabilities.

In Michigan, Sanders did extremely well (as always) among the young, winning 81 percent of voters aged 18-29. But this time he also did better than usual among the not-so-young (30-39), 53 percent of whom cast a ballot for him, as well as among independents. Sanders also won 31 percent of the African American vote, which is a much higher percentage than he had been managing in recent primaries across the South. If Sanders can consolidate and build on these patterns while continuing to do well among white liberals, he will likely keep nipping at Clinton's heels, and could even score a few more upsets in the upcoming primaries across the Midwest and Rustbelt.

Clinton would still likely win, but she would do so by relying to a distressing degree on unpledged "superdelegates" made up of members of the Democratic Party elite. Is that really how Clinton wants to prevail in a year when volatile populist passions are roiling both parties?

To change the dynamic of the race and give Clinton the power boost that she needs to surge decisively ahead of Sanders, the former secretary of state must do something bold to make fans of her opponent rethink their devotion to him.

She can do that with four words: Running mate Elizabeth Warren.

Long-time readers will recall that I've frequently turned to her as a dream candidate. A year ago I proposed that Warren and Jim Webb team up to form an unorthodox populist ticket that could appeal to working-class white voters as well as more typical Democratic constituencies. Then last fall, in a last-ditch effort to devise a way for Democrats to avoid putting all their chips on what I still consider to be the potential Clinton time bomb, I suggested that Joe Biden join up with Warren for…the same sort of economically populist option.

Neither panned out, of course. But despite residing several ideological clicks to Warren's right, I continue to consider her an admirable and appealing figure — and one who could help Clinton lock up the nomination and bring her party together as it prepares to confront whatever wildcard emerges from the ominous and chaotic free-for-all unfolding on the other side of the aisle.

To begin with, Warren has nearly as much left-wing populist cred as Sanders, but with one important difference: She actually knows stuff. Sanders is a very effective activist who hits his message about inequality and the corrosive role of money in politics with preternatural consistency. But he shows no sign of understanding the intricacies of how the worlds of banking, finance, or even campaign finance really work.

What he has is rhetoric. That's obviously very important when leading a movement and running for president. But it won't get you very far in governing — just as it's never gotten him very far in legislating. (And when the language includes numerous statements in praise of socialism and Fidel Castro's Cuban revolution, the words are also likely to prove politically radioactive in the general election.)

Warren has no such problem. Though she can rail against plutocracy (and Republican extremism) as passionately as any liberal Democrat, she's also an accomplished scholar who's an expert on bankruptcy law, consumer safety, and the regulation of the economy and personal finance. She served admirably as chair of the Congressional Oversight Panel that oversaw the controversial but absolutely essential Troubled Asset Relief Program during and after the financial crisis of 2008 — and proposed and established the Consumer Financial Protection Bureau, which protects Americans from abuse in the financial sector. Since her election to the U.S. Senate in 2012, Warren's considerable expertise in this area has shown through in her work on the Banking, Housing, and Urban Affairs Committee (and its subcommittee on Economic Policy).

By announcing a partnership with such a formidable and informed advocate for the safety and well-being of ordinary Americans, Clinton would show that she means what she says when she concedes points to Sanders while rejecting his blunt and ill-informed calls to "break up the banks."

And by making the announcement now, long before the Democratic convention, Clinton would manage not only to dominate the news for several days, but also (and more importantly) begin the process of unifying her party and preparing it to fight the Republican ranters and bomb-throwers in the fall.

Then there's gender. By putting together an all-female ticket, Clinton would contribute to consolidating the image of the Democrats as an inclusive, forward-looking party. This year, in particular, the contrast with the angry pessimism and locker-room vulgarity of the Republicans would be especially vivid.

The strongest case against Warren involves her lack of expertise in foreign affairs. That is indeed a concern. But is it more worrisome than the top of the ticket displaying a similar level of ignorance and choosing a running mate to balance out the deficiency? This is precisely what the past three presidents (Bill Clinton, George W. Bush, and Barack Obama) have done with their choice of running mates (Al Gore, Dick Cheney, and Joe Biden). I, for one, would vastly prefer that the nominee for president possess the requisite expertise in foreign affairs — which Hillary Clinton most certainly does — while the bottom half of the ticket learns on the job.

Elizabeth Warren is just what the Clinton campaign needs to silence the doubters and finally bring an end to the Sanders insurgency.