The rise of U.S. Sen. Kamala Harris was made possible by her ability to navigate between the poles of politics. She was elected San Francisco district attorney by unseating an incumbent to her left, became state attorney general by defeating a Los Angeles prosecutor running to her right, and won a U.S. Senate race in 2016 in a landslide over a 10-term Democratic congresswoman.

Now comes the big test: running for the Democratic nomination for president in a rapidly growing field in which she will be neither the furthest left at a moment when the party’s base is agitating for purity, nor the most experienced choice for voters desperate to bring seasoning and stability back to the White House.

But Harris, who announced her candidacy Monday with the slogan “For the People,” has always managed to find a winning lane. She begins the campaign among the upper tier of contenders, though the support is so diffuse at this early stage that it would be foolhardy to anoint anyone a favorite.

That Harris made it official on Martin Luther King Jr. Day was an unmistakable signal that she planned to accentuate her multicultural heritage — Jamaican father, Indian mother — as an asset for voters who have been repulsed by the racism and xenophobia tolerated and even encouraged in the Trump era.

Not surprisingly, her announcement drew a few shots from the left (focusing on her role as a prosecutor), and the Republican National Committee put out a statement scoffing at her as “arguably the least vetted Democrat” and “unqualified and out of touch.”

And so begins her quest to answer those and other questions sure to arise about her experience and ability to connect with voters far from San Francisco, in geography, culture and ideological perspective.

Those of us who have followed her career from the start expect her to be prepared, determined — and formidable.