(CNN) - Ask any Democrat considering running for president in 2020 about their decision-making process and most will draw a line between 2018 -- when it is far too early to decide -- and 2019 -- when the timing is just right.
A few Democrats haven't waited. Rep. John Delaney has been running for president for 17 months, while former Housing and Urban Development Secretary Julian Castro announced an exploratory committee earlier this month. And some have already bowed out, including lawyer Michael Avenatti and former Massachusetts Gov. Deval Patrick.
But plenty have been angling behind the scenes and the next two weeks, when the country briefly pauses for the holidays and possible candidates surround themselves with family, is likely to be significant in determining who runs for president in 2020.
Here is what some early contenders for the Democratic nomination have said about their decision-making process.
Former Vice President Joe Biden
For Biden, it's now or never. The 76-year-old Democrat opted not to run in 2016 and age will be a question if he runs this time around. If he doesn't run now, it's hard to see him having another chance.
"I'll be as straight with you as I can. I think I'm the most qualified person in the country to be president," Biden told an audience in Montana earlier this month. "The issues that we face as a country today are the issues that have been in my wheelhouse, that I've worked on my whole life."
Biden has previously said he knows he has to decide on a run by January 2019.
"I know I have to make up my mind and I have to do it by January," he said at a 2018 town hall.
Vermont Sen. Bernie Sanders
The story is similar for Sanders, whose unsuccessful run against Hillary Clinton in 2016 made him a top contender in 2020. But at 77 years old, Sanders likely has one more shot at the presidency.
"If there's somebody else who appears who can, for whatever reason, do a better job than me, I'll work my ass off to elect him or her," Sanders told New York Magazine in November. "If it turns out that I am the best candidate to beat Donald Trump, then I will probably run."
Sanders has called running for president a "very difficult decision for one's family."
He is expected to decide in early 2019.
Massachusetts Sen. Elizabeth Warren
Warren is preparing to run for president -- she has aides stockpiled in her Boston and Washington offices, has been talking to advisers about what a run would look like and plans are in the works to base a campaign in the Boston area.
And although Warren told CNN in March 2018 that "I am not running for president in 2020," she has begun to lean into making a decision in early 2019.
"It's time for women to go to Washington and fix our broken government, and that includes a woman at the top," Warren told a town hall crowd in Holyoke, Massachusetts. "So here's what I promise: After November 6, I will take a hard look at running for president."
Texas Rep. Beto O'Rourke
O'Rourke is the X-factor in the 2020 race. He lost to Sen. Ted Cruz in November in a closely watched race in 2018. But his youth and ability to compete in red Texas catapulted him to the upper echelon of presidential speculation -- something he has fed by backtracking on a claim that he won't run for president.
"Win or lose, I'm not -- I'm not running in, in 2020," O'Rourke said during a Texas Senate debate.
Since then, however, O'Rourke has said he will finish his House term and then make a decision.
"Then Amy and I will think about what we can do next to contribute to the best of our ability to this community," O'Rourke said.
California Sen. Kamala Harris
Harris looked to avoid the 2020 question throughout her efforts to campaign for Democrats in 2018.
"I am not bulls***ing you," she told CNN in October. "I don't know what this all means for 2020. It's really far off."
Since then, though, Harris has called the decision to run "a family decision."
"And over the holiday," Harris said in December, "I will make that decision with my family."
New Jersey Sen. Cory Booker
Booker, unlike some of his 2020 colleagues, hasn't been afraid to lean into his presidential aspirations.
"I will consider running for president," Booker told NJ Advance Media. "That's something that I will do. There's people in New Jersey who are talking to me about it, across the country that are talking to me about it, so I will consider that."
Booker traveled to New Hampshire in December and has been consistently calling elected officials and people he endorsed in early states, seemingly reminding them of his backing. The senator has also been talking to operatives in Iowa and New Hampshire, according to Democrats in each early state.
"Of course the presidency will be something I consider," Booker said in September. "It would be irresponsible not to."
Former New York Mayor Michael Bloomberg
The biggest question surrounding Bloomberg's possible run is how the Democratic Party, something he was not a part of before October, would accept a former Republican lawmaker.
"I will be a Democrat for the rest of my life," Bloomberg said in November, echoing a statement he made in September where he said it was nearly impossible he'd ever run as a Republican again.
"It's impossible to conceive that I could run as a Republican -- things like choice, so many of the issues, I'm just way away from where the Republican Party is today," he said. "That's not to say I'm with the Democratic Party on everything, but I don't see how you could possibly run as a Republican. So if you ran, yeah, you'd have to run as a Democrat."
Bloomberg has said that he would make a decision by early 2019.
"I think January, February would be about as late as you can do it and as early as you can gather enough information," he told the Associated Press in November.
Minnesota Sen. Amy Klobuchar
Klobuchar, whose run would hinge on her ability to win over rural voters like those in Minnesota, has been very clear that she will decide in early 2019.
"I will make that decision over the next few weeks, I've got to talk to my family," she said in December. "When I ran for the Senate last time, the first time I ran, my husband found out I was considering it on the radio. I'm not going to repeat that mistake again, that didn't work very well."
Klobuchar has traveled to Iowa -- her neighboring state -- and operatives in the first-in-the-nation caucus state believe, should she run, she would have to perform well in the state.
"I have been talking to people in my state and people around the country about it. I think that there are a lot of good people considering this, but I do think you want voices from the Midwest," Klobuchar said. "And I think you want to have people with different views running. I think it's really important to have that."
Ohio Sen. Sherrod Brown
The populist Ohio senator has said he has no timeline for a 2020 decision, but has framed the decision as something he must decide with his family.
"It's an intensely personal decision with my wife and my children," said Brown.
Brown has said, though, that he is being pressured to run.
"We're hearing it increase, so we're thinking about it as a result," Brown told the Columbus Dispatch in November. But "we're not close to saying yes."
Colorado Gov. John Hickenlooper
Hickenlooper gave an oddly specific answer when asked how close he is to running for president in December.
"We're probably 63, 64 percent," he told CNN. But people close to Hickenlooper tell CNN that the governor won't consider running until his gubernatorial term is over in January.
"My wife and I are still talking about it. We haven't made up our mind yet," the former brewer turned politician told the Brewbound Podcast. "But (if) you had a craft beer person like myself running for president, I think the industry would unite. I think the industry would come together and say, 'hey, we'd like to put a brewer in the White House.'"
Former HUD Secretary Julian Castro
Castro, unlike other possible candidates, has taken the first big step towards running: An exploratory committee.
"I'm exploring a candidacy for president of the United States in 2020 to renew the promise of this country for all," Castro said in December.
Castro later told CNN that he will make an official decision on January 12.
New York Sen. Kristen Gillibrand
Gillibrand has said she is "definitely" thinking about it and will take the holiday to talk to her children and husband about 2020, but she also backed herself into a rhetorical corner during her 2018 Senate run when she pledged to serve her full six-year term.
"I will serve my six-year term," she said, something she won't be able to do if she wins the presidency.
Even still, Gillibrand has leaned into considering a run.
"I'm definitely thinking about it, of course," she told Van Jones in December. "And I'm going to think about it over the holidays with my children and my husband, and I will make a decision soon."
South Bend, Indiana, Mayor Pete Buttigieg
Buttigieg has been honest about the long odds behind a possible 2020 run, but the South Bend mayor also took an important step in December when he opted not to run for another term as the chief executive of his town.
Buttigieg has also said that his timeline is relatively shorter than the bigger-name candidates.
"I think any candidate that is not already very famous probably needs to make some kind of move in January," said Buttigieg, who added that he is actually invigorated by entering the race with few expectations. "A field that is spread very thin probably works to the advantage of a newcomer if you are very good at it, and the only way to find out is to be tested in the field."
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