Kamala Harris is poised to be a historic — and influential — vice president

With her inauguration, Vice President Kamala Harris has made history: She’s the first woman — and first Black and South Asian person — to serve in the role, and now the highest-ranking woman in US government.

But beyond these firsts, Harris is poised to have an unusual vice presidency, in large part because of the singular role she’s expected to take on.

Harris will be one of just a handful of vice presidents to preside over a 50-50 Senate, making her a pivotal tiebreaker in the upper chamber. And given...