WASHINGTON, DC – The US presidential election in November is the most consequential in modern history. Whether the increasingly authoritarian, vindictive, and dangerous Donald Trump wins another four years in power could define the US for a long time to come.

This year’s election will be no typical struggle between two parties that differ more in degree than in kind. But first, the Democrats must select their candidate, and this time that contest is exceptionally fluid.

Former Vice President Joe Biden’s third attempt to win the country’s top job isn’t going much better than the first two. Biden is a well-liked figure – a decent, empathetic man who lacks a mean streak. But Biden’s very likability might well be his electoral undoing. He lacks what I call presidentialness – a certain dignity and remoteness that conveys the sense that crossing him or her would be unwise. He also lacks a message: reminding Democrats that he was Barack Obama’s vice president tells voters little about how he would govern.

Nor is it surprising that the air has gone out of Elizabeth Warren’s campaign. At the outset, she responded to questions by saying, “I have a plan for that.” She’s knowledgeable about domestic government and has attracted a passionate following. But she seemed not to grasp that enacting so many new programs would be impossible. Several of her Senate colleagues – including allies – told me early on that she wouldn’t “wear well.” They dislike her “holier-than-thou” attitude. There’s a coldness to her that all the selfies with fans don’t quite overcome.

Senator Bernie Sanders, too, is a victim of over-promising. He still does best among the youngest voters; most older voters question how he would pay for all his promises, including free tuition at public colleges and forgiveness of student debt.

Both Warren and Sanders have run into trouble with “Medicare for All,” universal health insurance. No one has shown how replacing Obamacare with a single-payer system wouldn’t raise taxes on the middle class, and some unions oppose it because it would replace the better health-care plans they negotiated, having given up other benefits. (Warren later adjusted her proposal, but not convincingly.)

Sanders, a self-proclaimed “democratic socialist,” is a worrisome figure at a time when party unity is seen as crucial to defeating Trump. Sanders’s ideological rigidity limits his following, and so he has failed to grow his constituency. Although he won New Hampshire, which borders his home state, Vermont, he won 50% fewer votes than in 2016. But right now, he cannot be ruled out as a strong possibility for the nomination.

Helped by a political press looking for a new story and by a good debate performance four nights before the New Hampshire primary, Senator Amy Klobuchar turned a third-place finish there (she was fifth in Iowa) into a “surge.” But debates are a poor indicator of a presidency: they test likeability, cleverness, and a vision, but they reveal little about candidates’ temperament, judgment, curiosity, wisdom, and diplomatic skill.

For now, Klobuchar’s bump has overshadowed her reputation for meanness in dealing with staff, which has caused difficulty in attracting and retaining top-tier aides. But Klobuchar also lacks a vision. She recites an apparently impressive record of winning elections in Minnesota, where she hasn’t had strong opposition, and emphasizes her modest origins (her grandfather was a coal miner). What she doesn’t point out is her corporate backing, including by the agribusiness giant Cargill, America’s largest privately held company – and one of the most controversial.

Pete Buttigieg, 38, has been the most surprising phenomenon in the contest, thanks to his sharp intellect and unusual composure. His rivals deride his political experience as mayor of a small city (South Bend, Indiana), but that has familiarized him with how federal programs work. He volunteered for the military and served in Afghanistan, and he’s given more thought to foreign policy than most of his rivals (except Biden). He handles being a married gay man with aplomb. He has a wry sense of humor and can subtly skewer an opponent in a way that recalls Obama.

But is that enough to win? Bill Clinton projected empathy. Americans saw Obama cry following the Sandy Hook elementary school massacre in 2012. It’s hard to imagine seeing Buttigieg cry. He can come off as the reserved McKinsey planner he once was. That, as much as controversial personnel decisions he took as mayor, may underlie his difficulty so far in attracting support from minority voters. And while one can imagine Buttigieg’s sharp intellect and quick sense of humor unnerving Trump, it’s unknown whether the electorate as a whole would be as accepting of a gay candidate as Democratic voters are.

Once Mike Bloomberg, a three-term New York City mayor, rose in opinion polls, he began to get closer scrutiny – which has landed him in choppy waters. For example, he has been accused of racism, essentially because of his “stop-and-frisk” program as mayor, and of misogyny in his business practices; vulgar statements he made before becoming mayor are now being circulated. But Bloomberg has drawn upon his enormous wealth to self-finance his campaign and build important alliances by donating to candidates and offering training grants to mayors, most of them black, and helping women advance.

Moreover, Bloomberg’s governing experience and his calm competence make him attractive to many. But his major draw is that he’s viewed as the best equipped to defeat Trump, who seems rattled by the prospect of facing a challenger who is far wealthier than he is (and evidently privy to his unseemly New York business practices).

To be able to buy political advantage may be unfair or wrong, but Trump is such an alarming figure that many voters so far appear willing to overlook what they would never forgive otherwise. That’s because the 2020 election is being fought at a time of crisis for American democracy.

Elizabeth Drew is a Washington-based journalist and the author, most recently, of Washington Journal: Reporting Watergate and Richard Nixon's Downfall.

© Project Syndicate 2020