Kamala Harris Takes the Spotlight, a Moment for Her and History

“There’s no way that you’re going to get, in this broad family, like everybody like, ‘Oh, you were my first pick,’” he said, even as he spoke enthusiastically about Ms. Harris.

If anything, the first two days of the convention were about the party trying to paper over any kinds of disagreements, aiming to present a united front of moderates and progressives, as well as some Republicans and democratic socialists. With elaborate videos and stage-managed speeches, Democrats showcased diversity — racial, gender, age — while nominating a 77-year-old white grandfather from Delaware as their standard-bearer. Party leaders gave small slots to liberals, though barely gave a platform to their policy goals like “Medicare for all.”

For the time being, the party’s desire to beat President Trump overrides all other factors. But if the Democrats succeed, Mr. Trump will be gone, and the challenge of satisfying the many constituent parts of the Democratic Party will become only more difficult for Ms. Harris, the figure who is supposed to be that bridge for generations and the face of the party’s future.

Like every vice-presidential candidate, Ms. Harris will be judged in the coming weeks in a multitude of ways: her ability as a campaigner, and her skill at drawing in President Trump, debating Mike Pence and exciting turnout among voters — particularly younger voters and progressives — who might not be overly enthusiastic about turning out in a pandemic to support Mr. Biden.

But as a woman of color seeking an office held only by white men so far, she may also be judged by some in ways that reflect deep-seated biases that remain strong in segments of the country. Ms. Harris took this subject on directly for her Democratic audience, and it is probably not the last time she will need to address it in the months ahead.