Who's running for president in 2020? List of Democratic candidates

The next presidential election isn't until Tuesday, Nov. 3, 2020, but there's already mounting speculation about which candidates will run.

Republican President Donald Trump officially formed his 2020 presidential campaign in 2017 and is expected (though not guaranteed) to clinch the GOP nomination, but the field is still wide open for Democrats and independent candidates hoping to run against him.

Several Democrats, including billionaire environmentalist Tom Steyer and former Massachusetts Gov. Deval Patrick, have declined to run in 2020. Here's a running list of just some of the candidates who are vying for the Democratic nomination.

Major potential Democratic candidates who launched exploratory committees or formally announced their candidacy

Sen. Bernie Sanders



2016 presidential contender Sen. Bernie Sanders will be joining the race again, he announced Feb. 19. Sanders, who was active on the midterm campaign trail as he endorsed liberal candidates around the country, emerged as one of the early favorites in the opening phase of the 2020 campaign even before his announcement.

Sen. Amy Klobuchar



Amy Klobuchar, a three-term senator from Minnesota, kicked off her campaign Feb. 10 in Minneapolis. She's the most prominent Midwesterner in the race so far and has drawn support from voters in urban, suburban and rural areas, including in dozens of counties Trump won in 2016.

She has said that success could translate to other Midwestern states such as Michigan and Wisconsin, reliably Democratic in presidential races for decades until Trump's victory over Hillary Clinton.

Sen. Elizabeth Warren



After announcing an exploratory committee on New Year's Eve, Sen. Elizabeth Warren formalized her bid for the presidency at a Feb. 9 rally in Lawrence, Massachusetts.

She's banking on a populist call to fight economic inequality, which she hopes will distinguish her and help her move past the controversy surrounding her past claims to Native American heritage.

Warren has spent the past decade in the national spotlight, first emerging as a consumer activist during the financial crisis.

Sen. Cory Booker



Sen. Cory Booker officially launched his campaign on Feb. 1, the first day of Black History Month. There was speculation Booker would run, as he was among the Democrats who were already testing their ability to connect with swing state voters, visiting Iowa, New Hampshire and South Carolina to build connections with key powerbrokers. Notably, Booker paced the stage at an Iowa Democratic Party fall banquet, repeatedly quoting Martin Luther King in a sermon-like speech to 1,200 of the state's most influential party activists, officials and donors in October.

RELATED: Things to know about presidential candidate Cory Booker

Sen. Kamala Harris


Sen. Kamala Harris (D-CA) officially launched her run by making the announcement on Good Morning America on Martin Luther King Day.


"The American people deserve to have someone who is going to fight for them...and put them in front of self-interest," she said.

Harris has served as a senator since 2017 after previously serving as the district attorney of San Francisco and California's attorney general.

RELATED: Things to know about presidential candidate Kamala Harris

Sen. Kirsten Gillibrand



After initially denying plans to run, New York Sen. Kirsten Gillibrand announced Jan. 15 that she had launched an exploratory committee for a 2020 bid.

RELATED: What to know about 2020 candidate, NY Sen. Kirsten Gillibrand

Gillibrand, who was appointed to the Senate in 2009 to fill the seat vacated by Hillary Clinton, has been among the Senate's most vocal members on issues like sexual harassment, military sexual assault, equal pay for women and family leave, issues that could be central to her presidential campaign.

As she works to distinguish herself from likely rivals, Gillibrand will be able to draw from the more than $10.5 million left over from her 2018 re-election campaign that she can use toward a presidential run.

Former Secretary of Housing and Urban Development Julian Castro



Former Obama administration housing chief Julian Castro officially kicked off his presidential campaign on Jan. 12.

Castro, the Democratic former mayor of San Antonio who served in President Barack Obama's second term, told Nevada Democrats Jan. 8 that as a presidential candidate, he's going to be talking about improving public education, equal treatment under the criminal justice system and addressing what he called the existential threat of climate change.

Former Rep. John Delaney



The three-term Maryland legislator announced his intention to run for the presidency back in 2017 and has since run multiple television ads in battleground Iowa. He visited each of Iowa's 99 counties in 2018, according to the AP.

Despite the nationalization of more recent presidential campaigns, Delaney has been taking a chapter from previous Iowa Cinderella stories. As a little-known Georgia governor, Jimmy Carter famously crisscrossed Iowa to emerge as a rising star in 1976.

Entrepreneur Andrew Yang



Andrew Yang filed a statement of candidacy in 2017. Yang is the founder of Venture for America, an organization focused on job creation in several cities across America. His campaign platform is focused on creating an "America of opportunity, freedom, equality, and abundance."

Rep. Tulsi Gabbard



U.S. Rep. Tulsi Gabbard, a Hawaii Democrat known for bucking the party establishment and for criticizing U.S. foreign policy in the Middle East, formally launched her campaign for president with a video posted online Thursday.

The 37-year-old Iraq War veteran is the first Hindu elected to Congress and the first member born in the U.S. territory of American Samoa. She has visited early primary and caucus states New Hampshire and Iowa in recent months and has written a memoir that's due to be published in May.

Pete Buttigieg, mayor of South Bend, Indiana



Democrat Pete Buttigieg, the 37-year-old mayor of South Bend, Indiana, said Jan. 23 he's forming an exploratory committee for a 2020 presidential bid.

Buttigieg has touted his work to improve his city of 100,000 residents as he's prepared for a jump from local politics to a presidential campaign. He's also said Democrats could benefit from a new generation of leaders as they try to unseat Trump in 2020.

Buttigieg is a Rhodes scholar who was first elected mayor of his hometown in 2011 at age 29, making him the youngest mayor of a U.S. city with at least 100,000 residents. A lieutenant in the Navy Reserve, he served a tour in Afghanistan in 2014.

Other high-profile potential Democrat candidates

Former Vice President Joe Biden



As he considers running for president, Joe Biden is talking with friends and longtime supporters about whether, at 76, he's too old to seek the White House, several sources who have spoken with the former Democratic vice president told the Associated Press in December.

The discussions suggest Biden is aware that his age may be the biggest hurdle to launching another bid for the Democratic presidential nomination, especially in an era when many in the party yearn for a new generation of leadership. If Biden runs against Trump in the general election, either would be the oldest president ever elected.

Biden will reportedly announce whether or not he plans to run by the end of January.

Former U.S. Rep. Beto O'Rourke



The outgoing Texas congressman's team said in December that he has no timeline or roadmap for deciding if he'd like to parlay a surprisingly close loss to Republican Sen. Ted Cruz into a White House try. People close to O'Rourke insist he hasn't expanded staff or lined up consultants even as the interest in him intensifies. They say he's spoken to top Democratic donors, but describe such discussions as fact-finding missions, researching the logistics of a possible run rather than securing assurances that coming campaign cash would go to him and not others.

Former Secretary of State Hillary Clinton



Could the 2008 and 2016 presidential hopeful launch another campaign? Back in October, Clinton said once again that she did not want to run again, though she added, "I'd like to be president."

She'd previously said she would not run again following her loss in 2016, though one of her former advisers predicted in a November Wall Street Journal op-ed that Clinton "will come full circle" and "fight this out until the last dog dies."

"She won't let a little thing like two stunning defeats stand in the way of her claim to the White House," Mark Penn wrote.

RELATED: Former Starbucks CEO Howard Schultz considering running for president as independent candidate, angering some Democrats

The Associated Press contributed to this report.