But who's in second? The answer to that question has been, for a very long time, easy: Bernie Sanders. It's not so easy anymore, thanks to the steady rise of Massachusetts Sen. Elizabeth Warren -- particularly among the most liberal voters that she and Sanders are competing most aggressively for in the race.

There's also the fact that Warren is a woman and Sanders is, well, not. If Warren can fight the "who's the most liberal of them all" question to a draw, the female voters who came up in droves to push Democrats back into the House majority in the 2018 midterms might just line up behind her 2020 candidacy, which could be decisive.

Below, our rankings of the 10 candidates most likely, as of today, to wind up as the Democratic presidential nominee. We update these rankings every two weeks, so if your favorite candidate isn't on the list -- or isn't as high as you think they should be -- just stay tuned. This is politics! Things change!

10. Julián Castro: Take a stroll through the baker's dozen of candidates we didn't include on this list. Now try to find one who has a more credible case than Castro, the former mayor of San Antonio. Castro is Latino and running on a message heavily focused on fighting President Donald Trump's immigration policies. And Castro is : Take a stroll through the baker's dozen of candidates we didn't include on this list. Now try to find one who has a more credible case than Castro, the former mayor of San Antonio. Castro is Latino and running on a message heavily focused on fighting President Donald Trump's immigration policies. And Castro is averaging 1% in national 2020 polling -- which isn't much, but is more than the people who could take his spot at No. 10. (Previous ranking: Unranked)

9. Andrew Yang: The movement of Yang to ninth place can be viewed one of two ways. The first is that Yang's doing better than expected, consistently getting at least 1% in The movement of Yang to ninth place can be viewed one of two ways. The first is that Yang's doing better than expected, consistently getting at least 1% in national polling . He even hit 2% in a Fox News poll out last weekend (and hitting 2% will be key to making the debates in September, when qualifications tighten up significantly ). The other way to see Yang's rise is that in a field of more than 20, the majority of so-called conventional candidates are doing poorly. (Previous ranking: 10)

8. Amy Klobuchar: The Minnesota senator remains, effectively, a non-entity in national primary polling -- clocking in at 1%. She's in marginally better shape in Iowa, where she's averaging just over 3%, : The Minnesota senator remains, effectively, a non-entity in national primary polling -- clocking in at 1%. She's in marginally better shape in Iowa, where she's averaging just over 3%, according to the Real Clear Politics polling average . Klobuchar would be smart to focus close to exclusively on the Hawkeye State where her Midwestern roots should, theoretically, help her gain some much-needed traction. (Previous ranking: 8)

7. Cory Booker: If there's one candidate who we might be underrating, it's this guy. Booker consistently sports some of the best favorable ratings in the field. For example, his favorable rating to unfavorable ratio was actually better than Warren's in a recent If there's one candidate who we might be underrating, it's this guy. Booker consistently sports some of the best favorable ratings in the field. For example, his favorable rating to unfavorable ratio was actually better than Warren's in a recent Monmouth University poll of likely Democratic Nevada caucusgoers. Yet, despite being well-liked, Booker was the first choice of just 2% of voters. The big question going forward is whether Booker can translate his base of goodwill among Democratic voters to votes from them. (Previous ranking: 7)

6. Beto O'Rourke: We weighed dropping the former Texas congressman below Booker, but in the end, kept him here because he remains slightly better off than the New Jersey senator in national and early state polling. But man, that's about all the good news we could find for O'Rourke, who continues to look totally lost as a candidate. Drawing the : We weighed dropping the former Texas congressman below Booker, but in the end, kept him here because he remains slightly better off than the New Jersey senator in national and early state polling. But man, that's about all the good news we could find for O'Rourke, who continues to look totally lost as a candidate. Drawing the first night's debate and being on a stage with fewer "star" candidates feels like an opportunity for a candidate who needs one badly. (Previous ranking: 6)

5. Pete Buttigieg: The mayor of South Bend, Indiana, received some of the best news of his campaign since our last rankings. He earned 14% among likely Democratic Iowa caucusgoers the The mayor of South Bend, Indiana, received some of the best news of his campaign since our last rankings. He earned 14% among likely Democratic Iowa caucusgoers the CNN/Des Moines Register/Mediacom poll . That was good enough for basically a three-way tie for second with Sanders and Warren. Additionally, Buttigieg looks like he's going to raise a ton of money this quarter, which will fuel his campaign and perceptions of it. The issue for him continues to be an inability to win nonwhite voters. He took 0% of them in a recent Quinnipiac University Florida poll of Democratic voters. (Previous ranking: 5)

4. Kamala Harris: The California senator got the : The California senator got the debate draw she wanted -- on stage on the second night with most of the candidates in front of her or running beside her in the race. That should make it easy for voters to make comparisons, and the Harris people have to like the dynamic of an African American woman debating three white men (Buttigieg, Bernie Sanders and Joe Biden) who she is competing against for the nomination. (Previous ranking: 3)

3. Bernie Sanders: The good news for the Vermont senator is that he is still in second place in The good news for the Vermont senator is that he is still in second place in most national polls . The bad news is in the trend lines. Sanders is down considerably since March. In some early state polling, he's either barely in second place or in third place (behind Warren). The one thing Sanders definitely has going for him is that he has a core of supporters who will never leave him. The question is how large is that core? The fact that Sanders is at just 15% suggests said core may be smaller than Sanders would want. (Previous ranking: 2)

2. Elizabeth Warren: The (re)rise of Warren speaks to the : The (re)rise of Warren speaks to the marathon nature of a campaign for president. The Massachusetts senator was the first major candidate into the 2020 race last year and got off to a decidedly weak start -- dogged by her failed attempts to put questions about her Native American heritage behind her. But Warren just kept rolling out policy papers, visiting early states and meeting voters. And it paid off . She is, at the moment, the candidate with the clearest momentum in the field -- and that's a good place to be. (Previous ranking: 4)