When Hillary Clinton ran for president in 2016, she had more than 200 distinct policy proposals. Four years ago, Joseph R. Biden Jr. had a task force write a 110-page policy document for his White House bid.

Now, Vice President Kamala Harris does not have a policy page on her campaign website.

A last-minute campaign born of Mr. Biden’s depreciated political standing has so far been running mainly on Democratic good feelings and warmth toward Ms. Harris, drafting off legislation and proposed policies from the man she is hoping to succeed.

Democrats’ problem for most of this year appeared to be Mr. Biden himself, rather than his policies. For more than a year, as his poll numbers sank, his aides and loyalists insisted that his legislative record and priorities were viewed favorably by Americans and would ultimately carry him to another term.

Ms. Harris is now testing that original theory — but with a younger, more spirited messenger.

On policy, she has essentially cherry-picked the parts of the Biden agenda that voters like most while discarding elements like his “Bidenomics” branding on the economy. She has emphasized what allies call the “care economy”: child care, health care and drug prices, which directly affect voters’ lives.

There is no area in which she is seeking a significant break from his agenda — perhaps not surprising given that she had a role in crafting much of it. She has abandoned a host of progressive positions she adopted while running for the 2020 presidential nomination, and has for the most part avoided getting bogged down in the specifics of what she would do as president.

“What they did is they cut out the unpopular parts of the campaign, which were all the questions around Joe Biden’s age and capacity, and they left in the popular parts, which were the actual record and the actual policies of the Biden-Harris team,” said Patrick Gaspard, the president of the Center for American Progress, the think tank of the Democratic establishment. “Now they have an opportunity to burnish those by projecting the unfinished part of the agenda into the future.”

Ms. Harris’s standard stump speech is hardly bereft of policy, though she does not delve into details. Instead, she calls for a broad range of policies embraced by mainstream Democrats.

As president, she says, she would seek to increase the minimum wage, introduce more robust child care and paid family leave programs, and keep down the costs of groceries, housing and prescription drugs. She has endorsed the bipartisan border security bill that former President Donald J. Trump helped tank early this year and the voting rights bill that House Democrats passed in 2021, only for it to run aground in the Senate. And Ms. Harris also calls for new gun control measures and makes an applause line out of her support for enshrining abortion rights into federal law.

This month, during a campaign stop in Las Vegas, she also endorsed a “no tax on tips” proposal that would have marginal impact on the nation’s tax policy but is popular in Nevada, where many casino workers rely on tips for their income. Mr. Trump called for a similar measure in June.

The Harris campaign late last month brought on Brian Nelson, a Treasury Department official who worked under her when she was the California attorney general, to be a senior policy adviser.

On Friday, after three weeks of delivering roughly the same stump speech, Ms. Harris made her first foray into policy with an economic address in North Carolina. She called for expanding the child tax credit, including a $6,000 credit for parents in the first year of a child’s life; proposed $40 billion in tax incentives for new housing construction; and endorsed a federal ban on price gouging — though she offered few details on how it would work.

“As president, I will be laser-focused on creating opportunities for the middle class that advance their economic security, stability and dignity,” Ms. Harris said.

Since she joined Mr. Biden’s ticket in 2020, Ms. Harris has rarely allowed differences in their policy to show — though she sometimes appeared to have less patience for the war in Gaza, and she seemed more interested in legalizing marijuana than he was. Aside from brief remarks last month about the Gaza conflict, she has said virtually nothing about foreign policy since Mr. Biden dropped out and she became the de facto nominee.

Running a truncated campaign, Ms. Harris does not have the time to draw out the sort of detailed policy proposals that have been hallmarks of recent Democratic presidential campaigns. It typically takes about two months for a presidential campaign to produce a high-quality, detailed policy document, but there is no shortage of off-the-shelf proposals that have been prepared for Mr. Biden’s administration.

And even then, it is not clear that it is politically wise for her to do so.

“I have not had a single constituent in El Paso or a single person on the road try to get very specific policy details from me,” said Representative Veronica Escobar, a Texas Democrat who is a co-chair of the Harris campaign.

In 2016, Mrs. Clinton nearly lost the primary race and then did lose the general election to candidates who ran feelings-based campaigns against her wonkery. In the 2020 primary contest, Senator Elizabeth Warren of Massachusetts bombarded voters with detailed plans and decorated the walls of her campaign offices with policy proposals. She never placed higher than third in any state.

Not to mention that Mr. Trump is hardly a paragon of policy. While his allies at the conservative Heritage Foundation produced the roughly 900-page book known as “Project 2025” that would reshape the country in his right-wing image, the former president has disavowed the document and said he would not abide by it if re-elected.

Mr. Nelson, the Harris policy aide, said that enacting Mr. Trump’s tariff proposals would mean significant cost increases for American families. The election, he said, is “a contrast with our opponent, whose Project 2025 agenda would raise prices by $3,900, repeal drug price negotiations and ban abortion.”

Still, Ms. Harris’s light-touch approach to policy is a stark difference from Mr. Biden’s approach in the summer of 2020, when to make peace with Senator Bernie Sanders’s defeated campaign, his team organized a series of groups to write proposals on criminal justice, education, the economy, the environment, health care and immigration policy.

Those proposals, people involved with crafting them said, were necessary because the party needed them to help unify people behind Mr. Biden’s campaign. This year, Representative Pramila Jayapal of Washington State, the chair of the Congressional Progressive Caucus, proposed to Anita Dunn, one of Mr. Biden’s top aides, that the groups be reconstituted for 2024.

Ms. Jayapal said in an interview on Friday that she had wanted to put the policy groups together to help young and progressive voters grow more interested in the flagging Biden campaign — something that she said was no longer a concern with Ms. Harris as the party’s nominee.

“We were consistently looking for how to build enthusiasm and excitement, as we continue to do,” she said. “It’s obviously very organic right now.”

Aside from brief remarks after meeting with Prime Minister Benjamin Netanyahu of Israel last month, Ms. Harris has said very little about foreign policy. She has also not addressed climate issues in any depth — though that is of little concern to Senator Edward J. Markey of Massachusetts, an author of the Green New Deal, who said Ms. Harris had earned her environmental chops by helping pass the Inflation Reduction Act in 2022.

“I know it’s in her DNA to be an historic environmental leader,” Mr. Markey said. “The first agenda has to be to win.”

While they are a minority, some Democratics do worry that Ms. Harris has not offered enough details about how she would accomplish her agenda.

Stacey Walker, a progressive former local elected official in Iowa who was part of the 2020 task force on criminal justice policy, said some liberals still had reservations about Ms. Harris’s background as a prosecutor — a remnant of the “Kamala is a cop” attacks from her last presidential campaign.

“There is power in the details,” said Mr. Walker, who added that he was “100 percent” behind Ms. Harris.

And Mr. Sanders said he expected that Ms. Harris would introduce more specifics about her plans before Election Day.

“As the campaign unfolds, I suspect there will be more details,” he said.

Roy Cooper, the Democratic governor of North Carolina and a top Harris ally, said 90 days was an “eternity” in politics and enough time for her to lay out a full policy platform.

“Getting all this legislation through this broken Congress has been an extraordinary achievement,” Mr. Cooper said. “So she’s got a lot to run on there, right? But she needs to lay her own groundwork.”

Still, many of Ms. Harris’s supporters subscribe to the notion that when it comes to policy in 2024, less is more. Even officials who spend their lives working on policy are reluctant to suggest that she produce any between now and Election Day. Her focus, they say, should be on doing whatever it takes to stop Mr. Trump from returning to the White House.

“Given that Trump only talks about relitigating the last election, a wall he never built, trying to distance himself from Project 2025 and something about sharks and Hannibal Lecter, the fact that the media is obsessed with the number of positions Harris has articulated to date is absurd,” said former Gov. Steve Bullock of Montana, a Democrat who in 2020 ran his own campaign for president.