Every election is called “the most important in our lifetime,” but this one really is. Because Trump’s unique pathology is seriously endangering our post-coronavirus health and our democracy, not since 1860 and 1932 has there been such a fateful choice for president. Depending on the outcome, our country may go headlong down the road to authoritarianism or return to majority rule.

Presumptive nominee Joe Biden has broken with tradition by announcing that he will choose a black woman for the first open Supreme Court seat as well as a woman as his running mate. “The most important thing,” he said about the selection of a running mate, “is that it has to be someone who, the day after they’re picked, is prepared to be president of the United States of America if something happened.”

While the six or so women who may be vetted each have their own strengths, Biden’s test of being “prepared” to be president on day one—not regional, racial or generational balance—suggests a clear favorite: Senator Elizabeth Warren. Based on her performance on the national stage as a presidential candidate, Warren is singularly ready to be a historic president if the situation arises because she’s a once-in-a-generation public talent with exactly the temperament and relevant economic, health, and anti-corruption policy experience to help Biden win and govern. Here are the reasons why:

She’s a policy “nerd.” During the campaign, her refrain was, “I have a plan for that”—and she did. Her 50-plus “plans” over the past year distinguish her as the only candidate ever whose campaign provided a de facto real-time transition report for the next president. Ever since she returned to her Senate office last month, her economic and health proposals to deal with the coronavirus pandemic have been widely touted. President Obama, for example—who doesn’t do things thoughtlessly—seemed to drop a big hint with a tweet to his 115 million followers that “as she often does [Warren] provides a cogent summary” of how to handle the pandemic.

She has always been a visionary and a leader. Warren was an early but ignored Paul Revere when she sounded the alarm before the 2007–08 fiscal crisis and then led the successful effort for a Consumer Financial Protection Bureau. Three years ago, she warned the Trump administration that it wasn’t doing enough to anticipate the next pandemic. As a presidential candidate, she had a fully developed federal cornavirus plan in January, and was the first to urge Trump’s impeachment after the Mueller report and to raise the subjects, among many, of reparations and a wealth tax.

She is a self-made success. Unlike Trump, who inherited millions, she was the first in her family to go to college; then it was on to law school and teaching law for 30 years at the University of Texas, the University of Pennsylvania, and Harvard. She also won an uphill race against a popular Republican incumbent senator in 2012 in Massachusetts. Warren comes from a working-class family and can be trusted by voters far from the Eastern or Washington establishments.

She’s a personable mensch. From her instinctive hugs for everyone to her kindness to staff to her “pinkie promises” with thousands of young girls, she embodies someone who is confident yet also grounded, compassionate, honest, and humble. And she’s funny.

She would be an effective “attack dog” if needed in the fall. One possible assignment for a VP nominee has been to expose the failings of the other ticket. Mike Pence should fear Elizabeth Warren if he saw her defenestrate Bloomberg in the ex-mayor’s first presidential debate, and also because Pence is obviously uncomfortable around women. (Will he even agree to debate on the same stage unless there’s a male moderator in between them?)

She’s a team player who works well with her peers, whether they are other professors, senators, or rivals. Warren easily shares credit with colleagues, and she listens to those with different opinions. She is an unusual combination of open-minded, bighearted, and strong-willed.

She has a gift for explaining the role of affirmative government. After the decades-long assault on the public sector—from Reagan to Gingrich to Trump—it’s urgent that the Democratic ticket show that the federal government exists to do what individuals, companies and states often cannot do, i.e., advance public health, security, and prosperity. “I believe in markets, but markets without rules is theft,” she often said in the campaign, adding that smart government should include “a consumer cop on the regulatory beat.”

This view has animated Warren’s career as a scholar, activist, and legislator. Based on her own pioneering research, she can clearly explain in plain language what’s happened to the average worker and middle-class family, and how intergenerational racial theft has cheated consumers of color. Her approach of “economic patriotism” can help people prosper at a time of widening inequality.

She proved to be a dynamic candidate in the presidential race, capable of exciting younger voters and progressive voters because of her story, views, and enthusiasm (notwithstanding her birth date). As for identity and regional concerns, Biden has just the “Joe from Scranton” appeal to reach non-college-educated white workers and, with Obama on the stump, a proven appeal to voters of color. Not surprisingly, national match-up polls show Biden doing better teamed with Warren than with any other proposed running mate.

The choice of Senator Warren would be lauded by nearly all Democrats, help “unify” the party by appealing to its two wings (especially disappointed Sanders supporters), reach out to the many Republicans and independents now frightened by Trump’s behavior, add flair to the fall ticket, and reflect well on the judgment of a nominee who chose a strong, talented woman to help him run the government, if not become a historic 47.

She’s the best. America deserves the best.