After a strong introduction, here’s what Kamala Harris needs to do now

For the large number of Americans still wondering who Ms. Harris really is, she and her party offered this week a stark contrast with the Republican ticket’s negativity — about the state of the country and its indispensable role in the world. “Our opponents in this race are out there denigrating America,” she said as she recounted her family’s only-in-America story. “I see a nation that is ready to move forward.”

In other words, she offered a strong introduction. Much depends on how she builds on it in the coming weeks.

The high energy in the convention hall reflected the enthusiasm Ms. Harris has inspired among Democrats. Yet some of the convention’s highest moments reached outside the party’s tent.

Republicans spoke, including former Georgia lieutenant governor Geoff Duncan, former congressman Adam Kinzinger of Illinois and former Mike Pence staffer Olivia Troye, in what Mr. Kinzinger termed a “somewhat awkward alliance that we have to defend truth, defend democracy and decency.” (Mr. Pence did not appear at the Republican National Convention and has said he won’t support former president Donald Trump.) A former Capitol Police officer, alongside a video showing the horrors of Jan. 6, 2021, offered a chilling reminder of Mr. Trump’s lowest moment and how the GOP has normalized a murderous mob. But these guests’ presence underscored a broader positive message, too: that the country should find unity in fundamental commitments to national ideals, the ones that compelled them to speak at a Democratic convention.

Last month’s Republican National Convention was about a man. Democrats, by contrast, did not try to create a cult of personality around Ms. Harris; four nights of programming showcased rising Democratic talents, including Maryland Gov. Wes Moore and Prince George’s County Executive Angela Alsobrooks.

Organizers sidestepped divisions inside their coalition that Republicans could have used to paint Democrats as extreme, averting a floor fight over whether the platform should call for an arms embargo on Israel. Protests outside the arena underwhelmed. An emotional high point of the week came when the parents of an Israeli American hostage spoke about their son and the crowd chanted “bring them home.” (The parents also called for an end to the suffering in Gaza.) Ms. Harris pledged to secure a cease-fire in Gaza that included the return of the hostages. In line with her message of upholding American values, she also promised to cultivate relationships with traditional U.S. allies and to stand with Ukraine against Russian aggression.

At the Republican convention, the crowd waved signs calling for mass deportations. At the Democratic convention, the program balanced calls for stronger border security by emphasizing the value of robust, continuing immigration and the need to give permanent legal status to the “dreamers.” The party’s platform also presented a more moderate face. Unlike 2020, for example, this year’s document no longer mentions Medicare-for-all.

Former president Barack Obama, as he spoke about the country’s pluralistic society, offered a subtle, but significant, rebuke of the woke left and cancel culture. Former president Bill Clinton called on the left to put away its litmus tests and gave Democrats a map for reaching moderate voters.

On kitchen-table issues, Ms. Harris promised to build an “opportunity economy where everyone has a chance to compete,” an appealing-sounding vision on which she will have to elaborate. Ms. Harris’s limited pre-convention economic proposals included some good ideas, such as boosting housing supply, and some rank pandering, such as special breaks for tipped workers, a key constituency in swing state Nevada. Democrats’ desperate attempts to blame inflation on price gouging misdiagnoses the problem and leads them to embrace corporate crackdowns that wouldn’t help. Ms. Harris did not mention one major constraint on government action: the runaway national debt. Nor did she say much about the degree to which government should act in the economic realm, preserving economic freedoms that spark dynamism and give innovation and entrepreneurship the space to flourish.

Democrats are excited. But as Ms. Harris fills in the blanks, there is no reason they shouldn’t push for a high standard.

“I will be a president who unites us around our highest aspirations,” Ms. Harris promised on Thursday. “A president who leads — and listens. Who is realistic. Practical. And has common sense.” Now she can show how.