In the week after earning plaudits for a powerful speech calling on the nation’s better angels to combat racism and hate and fight for the soul of America, former Vice President Joe Biden has stumbled into a danger zone with gaffes and misstatements that could cost him the Democratic nomination. Questions about his fitness to prevail in the grueling next nine months -- let alone the 14 till the general election -- have given progressives a huge opening, with Sen. Elizabeth Warren surging in popularity and momentum. And that is grim news for the Democratic Party.

As Biden creates doubts about his viability, there is no one else positioned to wrest support from the center of the electorate with a broad enough coalition to win in November 2020. Party elders can foresee a nightmare scenario in which Sen. Bernie Sanders fades, Warren consolidates enough support from his voters to topple Biden, then becomes the nominee and loses the general election.

Last weekend at the Iowa State Fair, when Biden made mistake after misstep and Trump proclaimed that he “isn’t playing with a full deck,” the contrast with Warren was painful. Her crowds were large and excited, his were not. Party operatives were abuzz over her stellar organization in the Hawkeye State where her campaign has spent months “embedding” in local communities and attending even small non-political events to ingratiate themselves among voters from every corner of the critical caucus state. Seasoned operatives say Warren’s organization and penetration in early states could make the difference in close contests once voting begins. While doubted and dismissed by the chattering class when she announced her candidacy, her grind-it-out, non-splashy campaign has finally broken through and captured the energy of hyper-engaged primary voters. Polling shows her surging nationally as well as in Iowa, and in some polls she is in second place.

Meanwhile, Biden’s support has softened. He could surely stabilize again and prevail, just as he did after a terrible debate in June panicked his supporters. Polling has consistently shown voters far prefer someone who can win rather than someone who represents their values. This has sustained Biden’s lead through months of attacks on his past opposition to busing, and support for the Hyde Amendment banning federal funding for abortion, the Iraq War, credit card companies and more. Biden is a known quantity, well liked, experienced as Barack Obama’s vice president and appeals to the middle of the electorate, particularly those in the Rust Belt, which gave Donald Trump the presidency by only 77,744 votes.

“Joe Biden can resonate with the working-class voters who Trump fooled in the last go-round. And that’s what we need: he’s close to the middle. He’s a known quantity. He appeals to middle-class voters,” the Democratic Party chairman of Iowa’s Madison County told the Washington Post last weekend, before warning, however: “There is starting to be a real fear that he cannot hold his own in the debate against Donald Trump.”

The whispers are mostly made off the record and on Twitter, not yet from major players in television or newspaper interviews, but the talk is the same: What if Biden is too outdated, fatigued and forgetful to make it another whole year to the nomination and then to next November, when he will be just shy of 78?

For now, Warren is the Little Engine That Can to Biden’s Big Engine That Perhaps Cannot. While the center of the electorate is reeling from our current turmoil and craves stability, Warren is promising “big structural change” and has eclipsed Bernie to become the beloved progressive in the race.

There’s a lot of talk about how the party should stop wasting resources and energy trying to win over white working-class voters who may have voted for Obama and then Trump, and that it instead needs to go after young voters, women and minorities. These voters, according to the left, will only vote for a progressive candidate who will inspire them. Biden wins with non-white voters and working-class whites, the coalition that has always chosen the party’s nominee. Warren does poorly with both; hers is a base of largely educated white voters. Implicit in the anti-Biden argument is that liberals think he can only attract African Americans who typically vote, not the ones who don’t vote and that they hope to “excite” and turn out next year.

A Biden fall clearly leaves the party far out on the left, without a strong contender for the center. Former Colorado Gov. John Hickenlooper had to drop out. Sen. Michael Bennett, former Rep. John Delaney and Montana Gov. Steve Bullock have yet to qualify for the debate next month (the deadline is Aug. 28). Even Rep. Tim Ryan, a congressman from Youngstown, Ohio who had a great debate in July and has a higher profile than all of them combined, hasn’t met the criteria for the next debate. (Another moderate, Rep. Seth Moulton, has never made it to a debate stage.) Sen. Amy Klobuchar is the only moderate besides Biden who has qualified for the next one, but – sorry, Amy -- she isn’t going to be the nominee. And yet dozens of moderate Democrats who gave the party the House majority last year, as well as plenty of Senate candidates, will be running against radical change and an Elizabeth Warren agenda.

Polling, for those Democrats who care to check, shows the country stands strongly against many of the far-out plans Democrats have told us about in the previous two debates. Decriminalizing border crossings, eliminating private insurance, reparations and providing health care coverage for illegal immigrants. Those are no-way issues.

Pile atop all that the many other liabilities the primary has exposed for Democrats. They’re nearly all for tariffs, save for Beto O’Rourke and Biden, yet can’t tell voters how they would restructure trade minus the war. They never approach the all-important subject of China, and offer little reassurance, again save for Biden, that they seek to return the nation to a post-America First leadership role in the world.

The woke are coming for Sleepy Joe. But if non-white voters stick with him through his old-man bumbling, it’s hard to see him losing the nomination. Perhaps African American voters can save the Democratic Party from itself. Biden against Trump is no slam dunk for Trump, no matter how many gaffes Biden piles up. There are likely more “Let Joe Sleep” voters out there than Republicans understand, voters who think Biden’s staff could run the country better than Trump is running it now.

Soon the polls will tell us if Democrats are willing to dump Biden, and how much they really want to win.