WASHINGTON (AP) — Vice President Kamala Harris is zeroing in on four potential candidates as she races to choose a running mate for her fledgling campaign, fast-tracking a process that usually takes months but must be finalized in only a few weeks.

Eric Holder, the former U.S. attorney general, and a team of lawyers at his firm Covington & Burling are taking the lead on vetting potential choices, according to two people with knowledge of the matter who requested anonymity because the process is being closely held.

The political conversation has centered on an assortment of white men — Arizona Sen. Mark Kelly, Pennsylvania Gov. Josh Shapiro, Kentucky Gov. Andy Beshear, North Carolina Gov. Roy Cooper — who would provide demographic balance for the first major party ticket that would be topped by a woman of color. Three of them are from battleground states.

The list of possibilities could expand or shift. But Harris, who has locked up the delegates she will need to be the Democratic nominee, hopes to finish the process in time for delegates to also vote on her running mate when they hold a virtual roll call vote in the first few days of August, ahead of the Democratic National Convention. The goal, according to one of the people with knowledge of the matter, is to keep the process drama-free, as Harris and Democrats try to project confidence after an extraordinarily tumultuous few weeks for the party.

Choosing a vice president is among the first major tests for Harris, and few people know the importance of the choice better than her. Four years ago, after Harris' own presidential campaign imploded, Joe Biden revived her political career by selecting her as his running mate.

Now that Biden has abruptly ended his bid for a second term less than four months before Election Day, Harris has swiftly established herself as his successor with the help of the president's endorsement. If Democrats formally nominate Harris, she would face off with Republican candidate Donald Trump in a race that's viewed by both parties as an existential battle over the country's future.

California Sen. Laphonza Butler, a longtime Harris ally, said the vice president views the choice as an "urgent but deliberate decision," and said Harris' own experience as a running mate would be a "grounding force."

Harris has seen "the importance of the working relationship, the trust, the energy and connection, as well as the shared values," Butler said.

Paul Begala, a longtime Democratic strategist, said Harris is lucky that the party has the "best bench I've ever seen in my entire career," providing an array of options for running mates.

He said there should only be one consideration for the choice.

"Forget the electoral college. Forget the polls," Begala said. "Pick the person that, if something happens, they can step into the job."

Begala recalled disagreeing with Bill Clinton's choice of Al Gore as vice president in 1992, arguing that the decision did nothing to expand the appeal of the ticket by pairing one moderate white man from a southern state with another.

Clinton rejected the advice, Begala said, by saying "I might die." The message was clear — Clinton thought that Gore could do the job if necessary and voters needed that assurance.

Dan Pfeiffer, a former adviser to President Barack Obama, said John McCain fumbled that test when he chose Sarah Palin, an inexperienced Alaska governor, in 2008.

"I know it's cliche, but the most important thing by far is the readiness test," Pfeiffer said. "It's table stakes."

Nine vice presidents have unexpectedly ascended to the presidency in American history. Eight of them did so after the president died from illness or assassination. Only one, Gerald Ford, became president because of a resignation, when Richard Nixon stepped down over the Watergate scandal in 1974.

The role of vice president, and the process for choosing a running mate, has evolved since the country's founding. Originally they were chosen not by the presidential candidates themselves but by convention delegates, usually in a deal intended to unify the party along geographic or ideological lines after a fractious primary.

"It often meant that the ticket consisted of two people who had different views on important issues," said Joel Goldstein, a vice presidential historian.

Goldstein said that began to change in 1940, when Franklin Delano Roosevelt demanded to choose his own running mate before he agreed to run for a third term.

One of the vice president's only constitutional duties is to preside over the Senate. But that role has become largely ceremonial except for the occasional tie breaking vote, and vice presidents more commonly serve as a top adviser, troubleshooter and emissary for the president.

"The consequences of the choice are greater because the expectation is that the vice president is going to be in the room and do consequential things," Goldstein said. "You can't dismiss him or her as easily as in the old days."

Trump chose his running mate, Ohio Sen. JD Vance, at the start of the recent Republican convention.

Vance is 39 years old, providing a jolt of youth to a ticket led by a 78-year-old man. A former venture capitalist who wrote a bestselling memoir, he's served just two years in the Senate.

Democrats swiftly criticized Vance as an extremist because of his support for strict abortion limits and for Trump's efforts to overturn his election loss in 2020.

Harris appears likely to choose a more moderate running mate, which could counterbalance her reputation as a liberal from California.

A few of the potential choices are, like Harris, former state attorneys general.

Beshear, the Kentucky governor, gained national recognition by beating Trump-endorsed Republicans in a red state. The son of a former governor, he's backed abortion rights and distinguished himself as an adept political communicator.

Shapiro has been a key advocate for Biden, and he's governor of the key battleground state of Pennsylvania. He would be the first Jewish person elected to the role of vice president.

Mark Kelly, a senator from Arizona, is a former astronaut and military pilot. He's also the husband of Gabby Giffords, the former Democratic representative who was grievously wounded in a 2011 shooting.

Cooper is a longtime North Carolina politician who has won six statewide elections. He's finishing his second term as governor, and he successfully worked with Republicans to expand Medicaid access under the Affordable Care Act.