AFTER FOUR HOURS of debating, 20 candidates, a lot of tweets, and one audio problem, the contours of the 2020 Democratic presidential campaign are becoming apparent — it’s starting to look like a two-woman race.

On Wednesday and Thursday nights in Miami, it was the Elizabeth Warren and Kamala Harris show. So much of these early debates are about affect and style, rather than substance. And Warren and Harris not only out-wonked their fellow candidates, they out-presented them.

On Wednesday, Warren was dwarfed on both sides by the much taller Beto O’Rourke, former US representative from Texas, and Senator Cory Booker of New Jersey. On Thursday, Harris had to compete with the two current Democratic frontrunners, former Vice President Joe Biden and Vermont Senator Bernie Sanders. Yet, both women displayed a fierce command of the stage that gave them a much larger presence.

Warren’s advantage comes from the fact that she has a clear, concise, and easily digestible message of broad, systematic change to level the economic playing field and end corruption in Washington. One doesn’t have to agree with Warren’s campaign themes, but there’s not much question as to where she stands. That certainty and willingness to take on controversial progressive positions — like shooting her hand up when asked if she would support scrapping private health insurance — projected strength in a way that few other Democrats could match. When Warren says, “I will fight for you,” it’s not just believable, it’s invigorating.

Harris’s edge on Thursday was equally pronounced — largely because of her similar passion and strength. The California senator demonstrated policy chops along with a willingness to take on Donald Trump directly, something that was oddly missing from the first night of debating. She showed compassion and empathy when she spoke of the harrowing decision by a migrant mother to bring her children to America, knowing the many perils along the way. But the key moment for Harris was her evisceration of Biden for his opposition to busing in the 1970s — deftly contrasting his retrograde position on the issue with her own experience as a child bused to opportunity.

For Democrats worried that a female candidate can’t go toe-to-toe with Donald Trump, Harris put such doubts to bed. She went at the current king in the Democratic field — and she did not miss.

The women’s two key rivals in the polls, Biden and Sanders, paled in comparison. Sanders didn’t have a bad night, but he didn’t have a great one either. His constant need to raise his voice and hector the audience is reminiscent of his debate performances in 2016 and has become grating and off-putting. But beyond style points, Sanders is trotting out the same tired message that he was peddling four years ago. Warren is making a similar us-vs.-them argument, but in a fresher and more compelling way.

As for Biden, I don’t think I’ve ever seen a worse debate performance by a presidential frontrunner. With the exceptions of Warren, Harris, Booker, Senators Michael Bennet and Kirsten Gillibrand, South Bend Mayor Pete Buttigieg, and surprisingly New York Mayor Bill de Blasio, most of the 20 candidates in Miami delivered weak or tepid performances. Few seemed to be presidential timber. But no one laid a bigger egg than Biden.

Even before Harris’s takedown, Biden was having a rough night — offering barely coherent answers and, frankly, showing his age. But the tête-à-tête with Harris exposed, perhaps, his greatest vulnerability — his thin skin. As the frontrunner, Biden had to know he would be attacked on Thursday, but he seemed utterly unprepared for it — and responded with misplaced umbrage, as if he is above such attacks.

His response to Harris’s questioning of his record on busing was defensive and tone deaf. The easy way out of the situation would have been to express contrition and move on. He could have taken a lesson from Buttigieg who, when asked about a recent police shooting in South Bend — and why blacks are so underrepresented in the city’s police force — said simply and remorsefully he “couldn’t get it done.” But Biden appears congenitally incapable of introspection or admitting error and on Thursday it did serious, perhaps enduring damage, to his presidential aspirations.

There is obviously a long way to go until Democrats start to cast ballots. But if the first debates of the 2020 campaign are any indication, the frontrunners aren’t looking so frontrunner-y and to quote an old Aretha Franklin/Annie Lennox joint, “sisters are doin’ it for themselves.”