Harris does have the "it" factor. She may not have it as much as Sanders '16 or Obama '08, but she has enough to get her a nomination, and more than any others. It's important that she has a double-breasted armor on the identity front; she'll be able to brand her male opponents sexist and her female opponents racist. But more than that, I think Democrats want a black woman. Remember the huge boom for Oprah earlier last year.
I sort of agree with the "it" factor analysis (potentially... we'll have to see how does campaigning in Primaries). I also agree that identity she brings when combined with the it factor is certainly a positive.
However, I disagree with the comparison to Oprah. The buzz around Oprah was due to her larger than life celebrity status- & very favorable ratings... not that she was a black woman.
I also disagree with the analysis regarding Harris being able to brand males opponents as sexist & females as whatever (not really sure the connection being drawn). This didn't work for Hillary- regarding Trump as sexist (which many people already thought- didn't need to brand him)...
And I doubt Harris would fall into the trap of trying to brand all opponents as sexist or racist- simply because they disagree with her or do not support her (which is different from doing so based on overt actions- such as the rallies in Charlottesville). Harris would likely be similar to Obama- reticent to use racism very often as an attack line towards opponents.
But I do agree Dems want a female & a minority on the ticket (not necessarily a minority woman)... And I think this is a good thing considering the HUGE majority of the Dem party is either a female or a minority (white males are probably less than 1/4th of the Dem Party makeup, so it only makes sense that such a party's Presidential ticket is not 2 white males. (in the same way that the republican presidential ticket being 2 black females is unlikely).