2020 Democratic presidential candidate field: Who's in, who's out?

Democratic governors, senators, U.S. House members, mayors and business titans are angling for the chance to take on President Donald Trump in the 2020 election. He's running; he never disbanded his 2016 campaign. Democrats are courting donors, hiring staff, booking flights to Iowa and New Hampshire, writing books and vying for TV time to make their case. One year from today, on Feb. 3, 2020, the Iowa caucuses will kick off the presidential election process. Democrat Hillary Clinton and Republican Sen. Ted Cruz of Texas were the caucus winners in 2016. These men and women won't all decide to run, and the eventual nominee could be a surprise after another rollercoaster campaign. But here's a look at who's capturing the buzz right now. Yes, already.

Says he's "most qualified" to run for the office.

Assets: High name ID, deep roots in party, linked to Barack Obama. Iowans like him best so far.

Challenges: He's 76 and has a long record, including some gaffes. He's run twice (1988, 2008) and lost. Not exactly new blood.

Plans to decide this month.

Assets: Billionaire businessman with progressive bona fides on gun regulations and climate change.

Challenges: Used to be an independent and a Republican. Backed disputed "stop-and-frisk" approach to fighting crime.

Announced that he's definitely in on Feb. 1.

Assets: Has an aggressive presence on Capitol Hill and visibility on social media. He says he's "fearlessly authentic."

Challenges: Faces a name-recognition deficit in a crowded field; relied on big donors in campaigns.

He's touring early-voting Iowa, New Hampshire, Nevada, South Carolina.

Assets: Won a third term last year in a state that no Republican has won the presidency without.

Challenges: He a populist on economic issues, less so on trade. Is a March decision too late?

He's been spending a lot of time in Iowa.

Assets: Hired top Democratic strategists and favors an assault-weapons ban.

Challenges: He'll need to boost his public profile. May not decide whether to run until the legislative session ends in April.

Announced an exploratory committee Jan. 23.

Assets: He's a gay Rhodes scholar and veteran of the war in Afghanistan, ran for DNC chairmanship.

Challenges: No mayors made a direct leap to Oval Office, but Calvin Coolidge and Grover Cleveland once presided over city halls.

Announced that he's definitely in on Jan. 12.

Assets: Family's background gives him immigration/wall credibility.

Challenges: He would be, at 45, the third-youngest person to become president. Fellow Texan Beto O'Rourke is the newest rising Democratic star.

He's been campaigning for the job since July 2017.

Assets: Early start includes multiple visits to Iowa, New Hampshire. Promises to pursue bipartisan ideas.

Challenges: But will he catch on with voters elsewhere? Do Democrats want a wealthy, white male businessman?

Tulsi Gabbard U.S. rep., Hawaii

Said she's running, but hasn't made a formal announcement yet.

Assets: She was the first Hindu and first American Samoan in Congress and served in combat in Iraq.

Challenges: Her campaign manager quit last week, suggesting disarray, and she's under fire at home.

She officially became a candidate on Jan. 15.

Assets: Says it's time for a woman and she votes against Trump policies.

Challenges: She's still blamed — not just in Minnesota — for shoving Sen. Al Franken out of office and once backed tougher deportation policies. Kamala Harris U.S. senator, California

She said on Jan. 21 that she's going for it.

Assets: She's a liberal black woman with a tough-on-crime background. California has new clout after moving its primary to early March.

Challenges: CSPAN fans know her, but polls show many voters don't yet.

He's hiring staff and odds favor a run, he says.

Assets: He'll leverage the state's track record on health care, environment and the economy.

Challenges: Needs to raise cash to introduce himself to voters, but money doesn't readily flow to unknown candidates.

He's "not ruling out" a run.

Assets: He's banking on the urgency of fighting climate change and creating clean-energy jobs.

Challenges: Is that enough when Democrats are itching to reverse multiple Trump policies? Some fellow Dem govs have criticized him. Amy Klobuchar U.S. senator, Minnesota

She's dropping hints that she's going to run.

Assets: She won big in last year's re-election bid and is seen — in stark contrast to Trump — as a calm, centrist pragmatist.

Challenges: A Washington Post columnist noted her "perceived lack of toughness."

Waiting and watching. "You never say never."

Assets: He has built a reputation for encouraging racial reconciliation and led a fight for removal of Confederate monuments.

Challenges: But can a white man effectively make those issues the centerpiece of a campaign?

Says he's "obviously looking" at a run.

Assets: Calls himself "compulsively optimistic." Backs a "realistic" Medicare-for-all plan.

Challenges: Longtime links to Clintons might turn off some voters. Former party chair's support might overlap with Biden's.

Beto O'Rourke Former U.S. rep., Texas

Not ruling anything out.

Assets: He became a star by almost beating GOP Sen. Ted Cruz and setting fundraising records.

Challenges: He's 46, which might make him a more plausible vice presidential candidate. National media focused recently on his "go-it-alone streak."

He's seriously considering running again.

Assets: He could capitalize on support and buyer's remorse from 2016.

Challenges: He's older than Biden, and some Democrats say his attacks doomed Clinton. He's apologized for campaign's sexual harassment issues.

Announced an exploratory committee Dec. 31.

Assets: Her economic populism could give her a blue-collar advantage in crucial Pennsylvania, Michigan, Wisconsin.

Challenges: The DNA test she took to prove American Indian heritage was widely viewed as clumsy.

Former Starbucks CEO Howard Schultz, entrepreneur Andrew Yang, author Marianne Williamson, former U.S. Attorney General Eric Holder, U.S. Sen. Jeff Merkley, U.S. reps. Eric Swalwell and Seth Moulton.

Confession: We put Trump in this group in June 2015. Things change.