Beto O'Rourke is lost. The former Democratic congressman, who unsuccessfully challenged Ted Cruz in last year's election, has spent the last few weeks in a confused and melancholy state. Something possessed him to share images from a recent dental cleaning, perhaps the grossest introduction of a potential presidential candidate in the nation's history. He gave an interview to the Washington Post where the only specific plank in his immigration platform was opposition to President Trump's border wall. In the same interview, he mused that the Constitution may no longer apply to the United States, since we're an "empire" with troops deployed around the globe and "trading agreements." Then he published a blog post that read like wannabe Kerouac. "Learned about pump storage, battery technology, the role that production tax credits have had in making New Mexico a leader in wind energy production," he wrote. O'Rourke himself has no trouble generating hot air.

Beto isn't merely the slightly flaky, out-of-work husband of a real-estate heiress. He's running third in polls of the 2020 Democratic presidential field. His emo style and recent missteps exemplify the weaknesses and vulnerabilities of the likely Democratic contenders. Judging from polls, Donald Trump is headed toward a one-term presidency. His best chance for reelection is pulling an opponent he can make as unpopular as he is. The Democrats seem more than willing to help him. In 1988, Democrats fielded the "seven dwarves" against George H.W. Bush. The 2020 cycle is shaping up to include 20 Smurfs. Trump is Gargamel.

The possible candidacy of Joe Biden links the two elections. His 1988 bid went nowhere, much like his run two decades later. Today, after eight years as Barack Obama's vice president, Biden is among the most popular Democrats in the country and leads the 2020 field. A poll last August had him beating Trump by seven points. But Biden faces significant hurdles before he reaches the general election. As much as Democrats like him, they'd also like to see "someone new." Biden's age (76), record of bipartisanship, insider status, and white hetero-normative cisgendered male identity might hinder his chances in the primary. It's noteworthy that former Obama advisers haven't swung behind him. Some have been talking up Beto, and others have encouraged additional candidates to enter the race. There's a reluctance to embrace Biden reminiscent of Republican wariness toward Mitt Romney in 2012.

Bernie Sanders, number two in the polls, has had one of the worst months of his career. Reports of sexual misconduct during his 2016 campaign have hurt him in a party where the #MeToo movement is sacrosanct. Sanders flubbed his response to the controversy when he told Anderson Cooper he was too busy running for president to address the bad behavior. Several members of his team don't want to join him this time. Bernie, like Donald Trump, benefited in 2016 from being the only alternative to Hillary Clinton. With Clinton gone and the Democratic field wide open, many Democrats expect his poll position to erode.

Elizabeth Warren has had a successful launch. She got out ahead of the competition. She seems to have put the controversy over her DNA test behind her by pretending it didn't happen. She's recruiting top party talent. She also has something most of the 2020 candidates lack—an actual policy agenda and story she wants to tell about the country. She'll have no trouble raising money. Her problem is consistently low favorability. That's led some Democrats to call Americans sexist, but there are plenty of liberal Democratic women more popular than Warren. For her to win the primary, much less the general, she needs to be more likable. Her grabbing a beer on Instagram didn't do the trick. But there's plenty of time and, after the American Indian heritage fiasco, Warren seems to be pulling together a professional campaign.

The election nerds are convinced Kamala Harris is the real frontrunner. She trails nationwide and suffers from low name ID, but she's popular among women of color. At 54, she's at the low end of the age spectrum for this Democratic field. Her book tour and "Mood Mix" are meant to raise her profile and emphasize her likability. But I won't be convinced of Harris's potential until she starts rising in the polls. She's never faced a competitive race. She's never encountered real scrutiny. She laughs too often at her own jokes. Her handling of a top staffer accused of sexual improprieties was far from flawless. Her record as a prosecutor is out of step with the party base. Does she have reasons for running beyond the abstract notion that she's the right fit for her party, and that victory against Trump appears guaranteed?

The other senators—Booker, Brown, Gillibrand, Klobuchar, Merkley—are no more impressive. There are plenty of theories that purport to explain why each of them should run, but politics doesn't conform to rational expectations. They also share the burden of running for president from the U.S. Senate. Barack Obama was the exception to the rule. He, John F. Kennedy, and Warren G. Harding are the only presidents elected directly from the Senate in 230 years of elections. None of the senators thinking of 2020 possess the political talent and cultural power of Barack Obama. None.

That leaves the governors and mayors. Jay Inslee, John Hickenlooper, Steve Bullock, Terry McAuliffe, aouigoiangoingogn—sorry, I just fell asleep.

The mayors are slightly more interesting: Mitch Landrieu, Eric Garcetti, Pete Buttigieg are novel in different ways. Unfortunately for them, a mayor has never been directly elected president of the United States. In fact, the only former mayor to become president was Grover Cleveland. Having covered a former mayor's presidential campaign in 2008, my message to these candidates is: Keep your day jobs. I am watching Michael Bloomberg, however. He doesn't mesh with the Democratic Party we see every day in the national media, but he's intelligent, shrewd, and willing to spend more money than Croesus on securing the nomination and defeating Trump. Only a fool would dismiss him.

Democrats go into 2020 with the advantage. They've won the popular vote in all but one election since 1992. The incumbent Republican is unpopular. But the perception of Trump's vulnerability is contributing to an unpredictable, grueling, and possibly self-defeating primary among up to two-dozen liberals of middling accomplishments. Recently I flipped through my dog-eared copy of Allan Lichtman's 13 Keys to the White House. Lichtman has an excellent prediction track record, including calling Trump's victory. (He opposes Trump.) When you look at the keys, which involve true-or-false statements regarding economic performance, corruption, social unrest, and foreign policy, 2020 remains too far away to call. Trump isn't out of the game. If the economy holds up, he'll be that much closer to reelection. Democrats need to understand: Lightning can strike the same place—and the same party—twice.