Michelle Obama spoke for decency. Three stories remind us how far America has to travel.

Michelle Obama’s speech this week was extraordinary in both its content and delivery. As many have observed, she is a highly credible presidential candidate herself and brought to the campaign a raw emotional blast against the abhorrent sexism and vulgarity of Donald Trump.

In a sense, the First Lady was doing what Clinton can’t. With just a few short weeks until the election, Hillary cannot afford to be labelled unfairly as a harridan or a man-hater.  She is conscious of all the baggage about Bill, which her opponent is happy to dredge up at every opportunity. So while she agrees with everything that was said this week by Mrs Obama, she needed someone else to say it.

The speech was about sexism and the treatment of women. It will rightly be remembered long after this tawdry and tortuous campaign season is over. But there’s another shadow that hangs over this election, as we all know. And that is the stirring of ugly racist sentiment – not just by Trump himself, but by a coterie of supporters and hangers-on, who see his elevation as carte blanche to turn the clock back and rail against political correctness.

I was struck by three recent stories of the modern US which probably won’t be remembered like Mrs Obama’s speech, but they all involve African-American women and they all demonstrate a sickening social malaise which seems to recur in bouts. No matter how much we think the illness has been cured, it returns and strikes again.

Dr Tamika Cross, who works at a hospital in Houston, Texas, was travelling on Delta Airlines when a passenger was taken ill. She claims she volunteered her services as a medic, but was addressed as ‘sweetie’ by a member of the cabin crew and told to sit back down, because the flight attendants were looking for an ‘actual physician’.  Once it eventually dawned on the dim-witted staff member that Cross was, in fact, a doctor, they still patronised her and deferred to another medically-qualified passenger, who happened to be a white male.

If her account is true – and there’s little reason to doubt it – then this is a shocking example of overt racism and sexism. In what small-minded world might someone’s life be put at risk because of prejudice over someone who was able to offer medical assistance?

Tasheema Chapman isn’t a doctor and doesn’t have a professional job. She is a single mother, who works in the Carl Schurz Park in the Upper East Side of New York City. She makes around $36,000 a year emptying bins and cleaning up.

Recently, when the park was hosting the Gracie Square Art Show, her supervisors asked her to clean dog mess off the shoes of one of the artists who was exhibiting there.  Understandably, she found the experience demeaning and humiliating, but felt she had no choice. She wanted to keep her job.

Was the fact that she’s a black woman significant here? You bet it was. Perhaps a white worker would have felt in a stronger position to argue with their bosses about this ridiculous assignment. And perhaps a white man would never have been asked in the first place.

The third story I read was about a mother in Chicago, called Tionna Norris. She received a note from her child’s teacher requesting that she use less coconut oil in her daughter’s hair, because classmates were complaining about the smell and teasing her. The young girl, Amia, had curly locks which needed regular moisture.

Commentators on social media wondered why the teacher wasn’t more concerned about stopping the teasing and bullying.  And her apparent lack of sensitivity to African-American culture and beauty regimens was thought to show prejudice and ignorance. There has been some speculation that perhaps she was the one who was concerned and that Amia’s classmates were, in fact, oblivious to any issue.

Three stories. Not of shootings and beatings and confrontations with police officers. Just three very different African-American women encountering ignorant and prejudiced attitudes which the United States finds so desperately hard to leave behind.

When Michelle Obama made her speech, she did so as the most powerful and recognisable black woman in the United States.  She will know, however, that despite her husband’s eight-year tenure in the White House, her country still struggles to come to terms with its history of racism, oppression and slavery.

And then, against this backdrop, comes Donald Trump.

We have reached the end of the democratic road with this guy.

He cannot win. He must not win.

Thankfully, all the polls now suggest that Hillary is far and away more likely to triumph on November 8^th.

If she doesn’t, it won’t just be a disastrous moment for American women. It will be a catastrophe for race relations in the United States too.

There is so much more work to be done. And while it has been an uphill struggle – even for a man with the courage and conviction of Barack Obama – it is essential that the US population continues the journey. That means choosing progress and enlightenment over prejudice and ignorance.