Now Kamala Harris is a 2020 candidate, Trump stands no chance at winning another election

Kamala Harris just ruined Donald Trump’s day. With her much anticipated declaration today, she immediately installed herself as a front-runner in the race to be the Democrat intent on taking down the president in 2020.

“Let’s do this together: For ourselves, for our children, for our country,” she said.

And with those carefully chosen words, Trump’s chances of reelection entered a death spiral. She is everything he is not.

In US elections the White House often swings to the opposite of what has gone before. And whether it is gender, race, age, or ideals, Harris represents the diametric opposite of the present incumbent. She is, in many ways, the "female Obama". The political symbolism of a woman of colour declaring her candidacy on Martin Luther King Jr Day was lost on precisely no one.

Certainly not on Trump, who will be feverishly trying to dream up a dismissive nickname for Harris. Such schoolyard tactics are unlikely to work. This daughter of a Jamaican-born father and Indian-born mother is a candidate of substance. She will spend the next year hammering Trump on his race relations record, specifically his comments after the neo-Nazi riots in Charlottesville. And voters will soon come to know the story of how, as a toddler, Harris was taken to civil right marches by her parents and shouted "Fweedom!" from her stroller.

Within her own party too Harris is breaking the mould. Joe Biden and Bernie Sanders are widely expected to enter the race in the coming weeks. But both are septuagenarian white men. Beto O'Rourke, for all his progressive credentials, is a millionaire internet entrepreneur. None of that is representative of the Democratic Party today.

It was notable in a recent analysis of social media interactions that Harris was an easy second to Alexandria Ocasio-Cortez, the young congresswoman, for the most engagement among Democrat politicians. She is connecting with the youth of the party. At 54 she is two decades younger than Biden and Sanders. Videos of her questioning of Brett Kavanaugh, Trump's controversial pick for the US Supreme Court, went viral, as have other episodes from her time on the Senate Judiciary Committee. And although she was only elected to the Senate in 2016, inexperience does not seem an argument that will fly for her opponents.

Her presidential campaign has been in the making pretty much since she arrived in the Senate, gathering support from donors and campaign professionals through last year. Earlier this month she published a book, a well-trodden path for candidates to get their life story known. That story is an immigrant story, of an American dream pursued by Harris's family, and it will resonate widely at a time when immigration is such a divisive issue.

When it came to announcing, Harris got one of the biggest platforms, a spot on Good Morning America, a sign the US TV networks know she is the real deal. It was a typically direct announcement, and Harris sought to address some of the concerns more national security-focused Democrat voters might have.

She stressed her 20 years as a prosecutor in California, and her commitment to "keeping America safe". Spelling out areas where she would take on Trump, she vowed to restore "America's moral authority in the world", working with allies he has snubbed.

Most of all, she vowed to "stand up and fight". And that is what the Democratic base most wants to hear.

There is no doubt, even among her opponents, about her strength of character, her will to succeed, and her ability to fight. The only question for her now is can she whip up crowds, generating the kind of fervour that Sanders did in the 2016 primaries? On the evidence so far she almost certainly can. She has a clear message, the CV for the job, and the X-factor that Hillary Clinton did not.

Harris, whose first name comes from the Sanskrit for lotus plant, has herself been in no doubt that her mould-breaking path to the White House will be far from smooth. Fortuitously though, she will have the advantage that California, her home state, has moved forward in the voting schedule from June to March in the 2020 primary season. This could give her a huge boost in the race for the nomination. However, Dianne Feinstein, the other Senator from California, has already backed Biden.

Harris will also be challenged on some aspects of her record as a lawyer in California. She has styled herself a "progressive prosecutor". But shortly before she announced her White House run she was slammed in New York Times by Lara Bazelon, a University of San Francisco associate law professor.

Bazelon contended that, as a prosecutor, Harris "fought tooth and nail to uphold wrongful convictions" that had been obtained through "evidence tampering, false testimony and the suppression of crucial information by prosecutors". Harris's advisers say her record is solid and they will be able to defend any such attacks. Considering the Clinton email scandal, and the various scandals surrounding Trump during the 2016 election, it would seem to pale into significance.

Energetic, charismatic, eminently electable, appealing to a wide cross-section of America, and scandal-free Harris is a dream Democratic candidate.