As US President Donald Trump faces intensifying scrutiny about possible connections to Russia, opposition Democrats are looking to 2020, and who might challenge the controversial leader for his job.
They have published new books and made repeat visits to early-voting states - traditional steps towards a White House bid.
Several have publicly expressed interest in running. "I'm considering it," goes the refrain.
Others are keeping mum for now. But with the first primary votes 14 months away, time is of the essence, and deciding late risks the best potential advisors - and donors - aligning elsewhere.
Trump is clearly eager to take on challengers. "I dream about them," he said recently.
The potential 2020 Democratic field is vast - too vast, some strategists worry. Meanwhile, some see it as a sign of party strength before waging campaign war.
The former US Vice President Joe Biden concedes that at 76, age may work against him in 2020. Source: AAP
The old guard
Joe Biden: Riding his fame and gaining sympathy over his son's death from cancer, the former vice president handily leads 2020 polls. But after eight years in the White House and a lengthy Senate career, Biden, 76, acknowledges that age is a "legitimate" election issue.
Bernie Sanders: Hillary Clinton's unexpectedly strong 2016 challenger has signaled his 2020 interest. The 77-year-old liberal US senator said he is studying whether he is the "best candidate" to beat Trump before launching a campaign.
Clinton and John Kerry: Both former secretaries of state lost their presidential bids, but they have delivered barely-cryptic messages about possible returns to politics.
Former Secretary of State Hillary Rodham Clinton has not ruled out another tilt at the White House. Source: AAP
The star of the moment
Beto O'Rourke: This 46-year-old progressive Texas congressman is suddenly the talk of the trail. While he lost his Senate race this month, O'Rourke gained an intangible asset: name recognition.
He built a national grassroots structure that reached millions, inspired an army of volunteers and won over independent voters - all critical for a modern-day successful campaign.
The wave of enthusiasm for the former punk rocker did not crash with his Senate defeat. Instead, he is routinely mentioned in 2020 analysis, and this week O'Rourke opened the door by acknowledging he is thinking about a presidential bid.
Some are not waiting for him to decide. A group called Draft Beto 2020, founded by Democratic strategists, launched this week to draw support.
The senators
Sherrod Brown: Often removed from the political spotlight, Brown acknowledged his presidential interest after the November 6 midterms.
His left-leaning policies on workers' rights and international trade played well in his Ohio, the quintessential Midwestern swing state where he resoundingly won re-election. Trump took notice, accusing Brown of failing to prevent the job cuts recently announced by General Motors.
Elizabeth Warren: The senator from Massachusetts still dodges questions about 2020 but the mystery is fading. On Thursday she outlined her foreign policy vision, and she regularly clashes with Trump on Twitter.
Cory Booker and Kamala Harris: The first-term Senate Democrats are popular progressives. Each this year has visited Iowa, the state that votes first in the nominations process, and other early voting states.
Harris and Booker, both of whom are black, are from California and New Jersey respectively, coastal states often associated with progressive elites, putting them at risk of a poor showing in heartland and southern states.
Senator Amy Klobuchar overwhelmingly won re-election in the Midwestern state of Minnesota, placing her in good standing should she announce a run.
Other senators mulling bids include Oregon's Jeff Merkley, New York's Kirsten Gillibrand, and Mark Warner of Virginia.
Elizabeth Warren has outlined her vision for foreign policy, leaving many thinking that she is serious about running in 2020. Source: AAP
The billionaires
Michael Bloomberg: Like Trump, Bloomberg is a confident New York billionaire. The ex-mayor has spent millions helping Democrats win in the midterms.
But Trump brushed him aside as a serious 2020 candidate this week, saying he would "love to run against Little Michael."
Oprah Winfrey: The television queen has denied interest in running, but her name keeps appearing on 2020 lists.
Financier-turned-environmental activist Tom Steyer, who has called for Trump's impeachment, is a potential candidate, as is Howard Schultz, the former chief executive of Starbucks.
Oprah Winfrey: Will she or won't she run in 2020? Source: AAP
The outsiders
With no heir apparent, the Democratic nomination fight will be sprawling. It could include governors like Montana's Steve Bullock, congressmen such as 40-year-old Seth Moulton, and Obama-era officials like ex-housing secretary Julian Castro - among others:
Michael Avenatti: The brash anti-Trump lawyer for porn star Stormy Daniels is "seriously" interested in a White House bid.
Richard Ojeda: The West Virginia military veteran who pumps iron, supports coal and once voted for Trump recently declared his candidacy.
John Delaney: The Maryland congressman became the first to announce his presidential campaign, in 2017, and has visited all 99 Iowa counties. He remains relatively unknown.
Senator Richard Ojeda addresses campaign supporters during his first campaign event of his presidential run. Source: Getty Images
