We learned a lot about the candidates last night, but the most important takeaway is that Sen. Kamala Harris is ready for the fight, and former Vice President Joe Biden is not.

Harris, who has shown her prowess grilling everyone from Supreme Court Justice Brett Kavanaugh to US Attorney General William Barr, came out of the gate with high expectations and went on to exceed them. She lit up the stage every time she spoke, which was often. And she came across as poised, poignant, and punchy, with the confidence of a chief executive.

When everyone was shouting and arguing over each other, Harris -- like a teacher taking control of an unruly class -- delivered the line of the night: "America doesn't want a food fight they want to know how to put food on the table”

And she showed no fear by directly attacking Biden’s record on race.

Biden, who had a terrible night, proved why it’s a miserable job being a part of the old guard when it seems the Democratic party is leaning toward diversity and a progressive vision for America. His fellow Democrats showed little deference, and Biden played defense much of the evening, too often leaning on his Obama crutch.

Two lines in particular characterized the depth of his challenge. Defending himself on race issues he responded with a line that sounded as figurative as literal: “My time's up, I’m sorry.” And when Rep. Eric Swalwell reminded him of times he talked about passing the torch, Biden painfully and unconvincingly declared, “I’m still holding onto that the torch.” Translated, “You can have my torch when you tear it from my dead, cold hands.”

Mayor Pete Buttigieg had a great night demonstrating why he has come from nowhere to be a top-tier candidate in a field crowded with better-known personalities. When he speaks, Buttigieg sounds thoughtful and earnest, without a hint of the over-rehearsed soundbite that often comes with more seasoned politicians.

It’s refreshing to hear a Democrat talk about faith and values. And having recently come under fire after a white officer fatally shot a black man in South Bend, Indiana, Buttigieg took responsibility for the lack of diversity on the police force by admitting, “I couldn’t get it done."

While many commended Buttigieg for his honesty, John Hickenlooper took advantage of the moment by pointing out that when he was mayor of Denver, Colorado, he diversified the police force and implemented de-escalation training years ago. Hickenlooper said, “The question they are asking in South Bend and across the country is why has it taken so long?” Ouch.

Many of the candidates had a decent showing, but what will be remembered after Thursday night is that Harris brought the fireworks, while Biden fizzled. Oh, and that Marianne Williamson will win with love.

Mark McKinnon is a former adviser to George W. Bush and John McCain, and creator and host of the documentary TV series "The Circus" on Showtime. Follow him on Twitter @mmckinnon.