During Vice President Kamala Harris’s presidential primary campaign in 2019, she developed a reputation she has been unable to shake — that she’s a messenger in search of a message. This idea has also characterized her tenure as vice president and driven some Democrats’ concern about her potentially replacing President Biden at the top of the ticket. But it is outdated.

In 2019, Ms. Harris was competing on progressive bona fides with the likes of Bernie Sanders and Elizabeth Warren. She was running at a time when progressive voters were uniquely focused on criminal-justice reform and suspicious of law enforcement, which was a problem for Ms. Harris, who had built her political career as a prosecutor. Hemmed in by these dynamics, Ms. Harris struggled to define her brand.

She faces a different moment today. Less than four months from the general election, she would be competing not for progressive points but to keep the felon Donald Trump out of office. She would be doing so at a time when many voters are concerned about crime and public safety, and when prosecutors have assumed heroic status in the fight to prosecute Mr. Trump and his cronies.

This time around, Ms. Harris could finally be herself.

When Ms. Harris began her primary campaign in January 2019, she had served just two years as a senator; the rest of her career had been spent as a state and local prosecutor. While this background had traditionally been a reliable path to political office on the right and the left, the politics changed during Ms. Harris’s career. By the time she was packaging herself for a national audience, so-called progressive prosecutors had been elected in cities across the country. These prosecutors promised to divert or decriminalize drug-related offenses, reform cash bail, decline to prosecute cases involving police misconduct and otherwise minimize the prosecutorial role.

In this context, Ms. Harris’s prosecutorial record was found wanting (including by me, in a profile I wrote of her in 2019). As district attorney, she threatened parents whose kids were chronically truant with prosecution. When Ms. Harris was attorney general, her office defended the death penalty and cash bail. During the primary, Ms. Harris tried to paint her record as progressive — compared with prosecutors in most American jurisdictions at the time, it was — but she was slow to take policy stands on criminal-justice issues. With just two years outside a prosecutor’s office, she lacked the depth that Mr. Sanders, Ms. Warren and Mr. Biden brought to most other issues. She made some embarrassing stumbles, such as taking contradictory positions on Medicare for all.

By the time Ms. Harris dropped out of the race, before the Iowa caucuses, she was widely perceived as rudderless. This reputation has followed her as vice president. Months into her term, she gave a disastrous 2021 interview with NBC’s Lester Holt on border policy. Rather than making additional appearances that might have shifted how voters saw her, she retreated, seemingly scared of making things worse. By last year, Ms. Harris had the lowest net-negative rating for a vice president among registered voters since the poll in question began.