With President Joe Biden’s support unleashing a flood of endorsements from many prominent Democrats across the country, Kamala Harris has emerged as the favorite to take his place as the party’s nominee for president.

Harris immediately received the endorsements of many Democratic party leaders and inherited the Biden campaign’s war chest. The campaign formally amended filings with the Federal Election Commission to rename its principal committee and declare Harris a candidate for president.

Now, the conversation is fast moving around who will serve as Harris’ running mate. With only 28 days until the Democratic National Convention begins in Chicago, where Harris presumably will be officially nominated, the scramble to find the Democrats’ vice presidential nominee has begun.

North Carolina Gov. Roy Cooper, Pennsylvania Gov. Josh Shapiro and Arizona Sen. Mark Kelly are among the Democrats who have been asked to submit information about their finances, family histories and other personal details, two people familiar with the process told CNN’s Jeff Zeleny. They are part of a group that includes about 10 names, nearly all of whom are elected officials.

Here are some potential candidates to run alongside Harris:

Josh Shapiro

Pennsylvania Gov. Josh Shapiro was elected in a landslide victory in 2022, defeating a 2020 election-denying far-right state senator to become the third Jewish governor elected in the crucial swing state.

Shapiro, who was previously Pennsylvania’s attorney general, had been floated by Democrats as a potential presidential prospect and is also considered a potential running mate to Harris if she is the party’s presidential nominee. During a stop in Philadelphia earlier this month, Harris called Shapiro a “great partner to the president and me.”

CNN previously reported that former President Barack Obama told Shapiro directly that he’s among the 2022 generation of Democrats who need to have a voice in the future of the party, according to people familiar with the conversation. Shapiro endorsed Harris on Sunday, calling her a “patriot worthy of our support.”

The assassination attempt against former President Donald Trump in Butler, Pennsylvania, has placed the governor in the spotlight. His response to the death of Corey Comperatore, the Trump supporter who was killed while shielding his wife and daughter, has especially been lauded.

“Corey was a girl dad. Corey was a firefighter. Corey went to church every Sunday. Corey loved his community,” Shapiro said at a news conference a day after the shooting. “And most especially, Corey loved his family.”

Roy Cooper

North Carolina Gov. Roy Cooper leads a state that is a crucial battleground in 2024. He was narrowly elected for the first time in 2016 by just over 10,000 votes. He won reelection in 2020 and is term-limited out of running for a third time. He endorsed Harris on Sunday, saying she “has what it takes to defeat Donald Trump and lead our country thoughtfully and with integrity.”

Throughout his time as governor, Cooper has clashed with lawmakers in the state legislature, where Republicans have a supermajority, over abortion rights and voting rights, among other things.

Cooper previously waved off speculation that he might be on the shortlist for vice presidential nominees if Biden steps aside and Harris becomes the nominee.

“I don’t want to play into this new favorite political parlor game, because it’s too important for America to stop Donald Trump,” Cooper told CNN in July. 

In office, Cooper overcame longstanding opposition in the state’s Republican-led legislature and achieved one of his top priorities last year when the North Carolina became the 40th state to expand Medicaid to low-income adults. More than 500,000 residents now have coverage through expansion. Biden and Harris heralded the achievement during a joint campaign stop in Raleigh in March in hopes of winning the state.

First elected to the North Carolina House of Representatives in 1986, Cooper has been a force in North Carolina politics for years. He rose to be the Democratic majority leader in the state Senate, and won his first statewide race for North Carolina attorney general in 2000. He held the post for four terms.

Mark Kelly

Arizona Sen. Mark Kelly represents a state that Biden won by only 10,457 votes in 2020 and has national name recognition both as a former astronaut and the husband of former Rep. Gabby Giffords.

He has been a reliable supporter of Democratic Party priorities while in office but has occasionally bucked his party, such as in 2023, when he flatly called the influx of undocumented migrants across the US southern border a “crisis.”

If Kelly, who swiftly endorsed Harris for president on Sunday, was elected to higher office, his seat would remain in Democratic hands as Gov. Katie Hobbs would be able to appoint his successor.

Andy Beshear

Kentucky Gov. Andy Beshear has been floated as a possible vice-presidential candidate. He won reelection to a second term last November in a deep-red state that Trump carried by about 25 points in 2020. He’s the top elected Democrat in the Bluegrass state and made abortion a major issue in his campaign.

After endorsing Harris, Beshear wasn’t shy about expressing his willingness to run alongside her if asked.

“Are you at least open to the possibility of being a running mate to Vice President Harris?,” Beshear was asked on MSNBC Monday morning.

“Well, I think if somebody calls you on that, what you do is, is at least listen,” he replied.

Beshear is one of the nation’s most popular governors. He’s made headlines for his leadership of the state through the Covid-19 pandemic, deadly tornadoes in 2021 and catastrophic flooding in 2022.

Should Republicans retain control of the House and gain a majority in the Senate, he has experience navigating clashes with GOP lawmakers. He previously served as state attorney general before winning a narrow gubernatorial victory in 2019, and his time as governor has been marked by disagreements over education, public assistance and tax policy with the Republican-led state legislature.

His father, Steve Beshear, was Kentucky governor for two terms and received national attention for lowering the state’s uninsured rate from more than 20% to 7.5%, one of the country’s largest improvements following the implementation of the Affordable Care Act.

J.B. Pritzker

Illinois Gov. J.B. Pritzker, heir to the Hyatt hotel riches, was first elected in 2018 and sailed to reelection in 2022 by more than 10 percentage points.

Pritzker, who endorsed Harris on Monday morning, has navigated a series of issues that have dominated the 2024 presidential race, from gun control to reproductive rights. He’s led the state as it contends with increased demand for abortion care from women forced to travel from the South and Midwest in a post-Roe v. Wade era. In 2023, Pritzker signed an extensive ban on firearms and high-capacity magazines.

He also signed first-in-the-nation legislation that prohibits book bans in the state. The governor, along with Chicago Mayor Brandon Johnson, also confronted top White House officials in October over the migrant crisis they warned was near a breaking point.

Pete Buttigieg

Transportation Secretary Pete Buttigieg styled himself as a centrist during his 2020 campaign for the Democratic presidential nomination, leaning in on his time as the mayor of South Bend, Indiana, and his service in the Afghanistan War. His presidential run was historic: He was the first openly gay man to launch a competitive campaign for president, he broke barriers by becoming the first gay candidate to earn primary delegates for a major party’s presidential nomination, and also became the first Senate-confirmed out LGBTQ Cabinet secretary in history.

It’s been an eventful tenure for Buttigieg leading the Transportation Department: he was criticized for what was viewed as a slow federal response to the 2023 trail derailment in East Palestine, Ohio, and he has often served as the Biden administration’s leading critic of the airline industry following flight delays and other mishaps. As a potential Harris running mate, Buttigieg would be an effective attack dog: he memorably called then-Vice President Mike Pence, an evangelical Christian, a “cheerleader for the porn star presidency,” a reference to Trump’s personal life, and has delighted liberals on social media by sparring with Fox News panelists.

Buttigieg previewed how he’d take on Republican vice presidential nominee JD Vance on HBO’s “Real Time with Bill Maher” recently. He said he “knew a lot of people like” Vance, a Yale Law School graduate, at Harvard.

“I found a lot of people like him who would say whatever they needed to, to get ahead. Five years ago, that seemed like being the anti-Trump Republican, so that’s what he was. … Five years later, the way he gets ahead is (Trump) is the greatest thing since sliced bread,” Buttigieg said.

Gretchen Whitmer

Michigan Gov. Gretchen Whitmer, who won reelection in the crucial swing state in 2022 by roughly 10 percentage points, was eyed by Democrats as a top candidate to replace Biden atop the ticket, though she endorsed Harris on Monday morning and appeared to take herself out of consideration in comments to local reporters.

“I am not leaving Michigan. I am proud to be the governor of Michigan. I have been consistent. I know everyone is always suspicious and asking this question over and over again,” she told local reporters, The Detroit News reported. “I’m not going anywhere.”

Whitmer, first elected governor in 2018, emerged as a prominent executive during the height of the Covid-19 pandemic. Her leadership decisions, which included stay-at-home orders, made her the target of a kidnapping plot in 2020.

During her time in office, Whitmer has also prioritized efforts to expand affordable access to health care. She has invested billions of dollars in the state’s infrastructure and created a department tasked with improving the quality of drinking water in Michigan. She’s also pitched herself as a staunch defender of reproductive rights.

In the weeks following the debate between Biden and Trump, Whitmer continued to voice support for the president, brushing aside rumors that she might step into the race should he withdraw.

“I understand that some are playing fantasy football and want to just pick a couple of random leaders that they like across the country and design a ticket. That’s just not how this works,” she told CNN’s Abby Phillip earlier this month. “We have a president who’s gotten a nomination, who’s earned it.”

Gavin Newsom

California Gov. Gavin Newsom was the subject of 2024 presidential speculation last year, when he notably debated then-GOP candidate Florida Gov. Ron DeSantis on Fox News and visited several Republican-led states. He moved to endorse Harris on X Sunday evening, writing, “no one is better to prosecute the case against Donald Trump’s dark vision and guide our country in a healthier direction than America’s Vice President, @KamalaHarris.”

Like other Democratic governors who have been floated as potential 2024 picks, Newsom steered his state through Covid-19. He fought off a recall effort in 2021 that stemmed from partisan anger over his pandemic response. Newsom also received blowback for attending the unmasked birthday dinner of a lobbyist friend at an elite Napa Valley restaurant at a time when he was urging Californians to stay home.

First elected in 2018, Newsom has called for Democrats to go on the offensive, calling out the GOP’s stance on abortion restrictions, book bans and protections for the LGBTQ community, among other things. He was mayor of San Francisco from 2004 to 2011.

If Harris becomes the Democratic nominee, Newsom, a fellow Californian, would run up against the 12th Amendment of the Constitution, which would prohibit Golden State electors, all 54 of them, from voting for a president and vice president who share the same state as themselves. Theoretically, this snag could be avoided if either Harris and Newsom changed their official residencies, potentially even after the election but before the Electoral College meets.

CNN’s Tami Luhby, Ethan Cohen, Jasmine Wright, Devan Cole, Gregory Krieg, Edward-Isaac Dovere and Dan Merica contributed to this report.