Michelle Obama just made the most compelling argument for Hillary Clinton we've heard.

Michelle Obama had a very important job at the Democratic National Convention, and she absolutely excelled at it.

Taking the stage to endorse Hillary Clinton, Mrs Obama gave a personal, moving and compelling speech centered around her two daughters, Malia and Sasha.

“During our time in the White House we have had the joy of watching them grow from bubbly little girls into poised young women,” she began.

“A journey that started soon after we arrived in Washington when they set off for the first day at the new school.

“I will never forget that winter morning as I watched our girls, just seven and 10 years old, pile into those black SUVs with all those men with guns. And their little faces pressed up against the window, and the only thing I could think was, ‘What have we done?’

“At that moment, I realised that our time in the White House would form the foundation of who they would become. And how well we manage this experience could truly make or break them.

“That is what Barack and I think about every day as we tried to guide and protect our girls from the challenges of this unusual life and the spotlight.

“How we urged them to ignore those who question their father’s citizenship or faith. How we insist that the hateful language they hear from public figures on TV does not represent the true spirit of this country. How we explain that when someone is cruel or acts like a bully, you don’t stoop to their level. Our motto is, when they go low, we go high.

“With every word we utter, with every action we take, we know our kids are watching us. We as parents are the most important role model.”

She highlighted Hillary Clinton’s decades of public service and praised her support for Obama, even after losing a bitter primary battle.

Click through for a glimpse of Michelle Obama’s Instagram. (Post continues after gallery.)

And she also identified the extra-special quality of Hillary Clinton’s campaign, not easily quantified or articulated.

“Leaders like Hillary Clinton, who have the guts and the grace to keep coming back and putting those cracks in the highest and hardest glass ceiling until they finally break through, lifting all of us along with her. That is the story of this country,” she said.

“The story that has brought me to the stage tonight. The story of generations of people who felt the lash of bondage, the shame of servitude, the sting of segregation, who kept on striving, and hoping, and doing what needed to be done.

“So that today, I wake up every morning in a house that was built by slaves. And I watch my daughters — two beautiful intelligent black young women — play with the dog on the White House lawn.

“And because of Hillary Clinton, my daughters, and all of our sons and daughters, now take for granted that a woman can be president of the United States.”

Hillary Clinton might not be there yet, but Michelle Obama made it very clear she’s going to do everything she can to make President Hillary Clinton a reality.

The speech came among a middling night at the Convention, with “Bernie or Bust” Democrats booing their preferred candidate Bernie Sanders when he implored all Democrats to unite behind Clinton.

Five Thirty Eight, the blog famous for its accurate predictions of electoral outcomes based on polling aggregation, now has Republican candidate Donald Trump’s probability of winning the November general election at just over 46 per cent.

Clinton is at just above 53 per cent.

Michelle Obama’s speech was a vital injection of energy and optimism, as the Democrats prepare to officially nominate the first major party female candidate for President in US history.

And the crowd went wild.