(CNN) There are 1,281 days between today and the Nov. 3, 2020 presidential election. But, with Donald Trump in the White House, Democratic politicians are already eagerly jockeying for position with the expectation that the party's nominee will have a very good chance of ousting the incumbent -- if his poll numbers stay anywhere as low as they are at the moment.

One potential candidate who looks like she's decided against running is New York Sen. Kirsten Gillibrand. "I'm focused entirely on running for Senate, so yes, I'm ruling it out," she said Monday in New York

Gillibrand's announcement is a bit of a surprise given that she was widely seen as a likely candidate. (She, of course, could change her mind sometime between now and 2020. See " Obama, Barack " on that front.)

Gillibrand's news got me to thinking: Just how many people are thinking about/mentioned/floating themselves for the Democratic nomination and where, roughly, do they fit when it comes to their chances of winning?

Below I broke the field into four tiers as a way to think about the massive number of potential competitors. These names -- and the groups they fall into -- are based on email exchanges with more than a dozen national Democratic strategists, many of whom are veterans of the Obama and Clinton campaigns.

One grain of salt before we proceed. A prominent Democratic consultant offered this analysis of the current field: "I don't think there is a top tier. I think our bench is that weak so everyone starts in Tier B."

Also, I've placed them in alphabetical order within their respective tiers.

1st Tier (If they run, they have a real chance to win the nomination)

Joe Biden

JUST WATCHED Who is the leader of the Democratic Party? Replay More Videos ... MUST WATCH Who is the leader of the Democratic Party? 04:59

The former vice president clearly regrets not running in 2016. And he's keeping the sort of schedule -- New Hampshire speech! -- that makes him look like someone who's thinking of running.

Bernie Sanders

JUST WATCHED Sanders: Obama's paid speech not a good idea Replay More Videos ... MUST WATCH Sanders: Obama's paid speech not a good idea 00:47

The Vermont independent started a movement in 2016. His grassroots activist and donor base is bigger than anyone in the potential 2020 field.

Elizabeth Warren

JUST WATCHED Sen. Warren's full interview with Jake Tapper Replay More Videos ... MUST WATCH Sen. Warren's full interview with Jake Tapper 07:16

Warren, prior to 2016, was the face of the populist, anti-Wall Street wing of the Democratic party. Sanders cut into Warren's dominance in his presidential campaign. But, she remains the single most beloved figure among liberals.

2nd Tier (Have potential to be a major contender but not there....yet)

Cory Booker

JUST WATCHED Booker: Exec order on sanctuary cities hurts police Replay More Videos ... MUST WATCH Booker: Exec order on sanctuary cities hurts police 05:21

Andrew Cuomo

JUST WATCHED Cuomo announces proposal for free tuition Replay More Videos ... MUST WATCH Cuomo announces proposal for free tuition 01:03

A two-term governor of New York with a record of liberal accomplishments and a famous last name? Check, check and check.

Al Franken

JUST WATCHED Watch the full interview with Sen. Al Franken Replay More Videos ... MUST WATCH Watch the full interview with Sen. Al Franken 05:33

The Minnesota Senator emerged as one of the leading critics of Trump's Cabinet picks in the early days of the administration. And he's gone from a sideshow to a serious legislator in his eight years in the Senate.

Kamala Harris

JUST WATCHED Kamala Harris: Boycott about transparency Replay More Videos ... MUST WATCH Kamala Harris: Boycott about transparency 01:05

The newly-minted California senator is avoiding any talk about her future ambitions. But her history-making Senate bid -- she's the first Indian American and first black senator from California -- and the state's size and massive Democratic dominance makes her appealing

Jay Inslee

JUST WATCHED Democratic Governors plot a 'vigorous 2018' Replay More Videos ... MUST WATCH Democratic Governors plot a 'vigorous 2018' 00:43

That so few people in Washington buzz about the two term Washington governor is a pretty obvious case of East Coast bias. Inslee has spent time in Washington (D.C.) as a member of Congress and got a major media boost from his state's role in blocking Trump's travel ban

Tim Kaine

JUST WATCHED Kaine: Trump trying to stay cozy with Russia Replay More Videos ... MUST WATCH Kaine: Trump trying to stay cozy with Russia 02:11

The 2016 vice presidential nominee has insisted he won't run for the top job in 2020 . I take him (mostly) at his word, so he sits in the 2nd tier. But if Kaine runs -- particularly with the blessing -- and endorsement(?) -- of Hillary Clinton he could be formidable.

Terry McAuliffe

JUST WATCHED VA governor on Trump's infrastructure plan Replay More Videos ... MUST WATCH VA governor on Trump's infrastructure plan 01:48

The Virginia governor is term-limited out of a job later this year and there is already chatter about what he might do next. And, his prominent role leading Democratic redistricting efforts gives him a national platform and fundraising base. Also, the Clintons.

Chris Murphy

JUST WATCHED Murphy: Trump lied to reporters on immigration Replay More Videos ... MUST WATCH Murphy: Trump lied to reporters on immigration 01:33

The Connecticut Senator's profile has soared since the tragedy in Newtown in December 2012. Murphy has not just emerged as a lead voice on gun control but also as a point man in attacks on Trump. Some whisper he is too green and ambitious. But that's rarely a hindrance in presidential politics.

3rd Tier (There's a chance but....)

Steve Bullock

There was no recent CNN interview with Montana Gov. Steve Bullock

The governor of Montana is a Democrat. Did you know that? Probably not. That's Bullock's problem. But, if Democrats are looking for new voice from the Mountain West, he has a puncher's shot.

Eric Garcetti

JUST WATCHED Mayor of L.A. ready to stand up to Trump Replay More Videos ... MUST WATCH Mayor of L.A. ready to stand up to Trump 01:30

The popular mayor of Los Angeles is mulling runs for governor in 2018 and president in 2020 . President seems like too big a leap. Particularly with fellow Californian Kamala Harris lurking.

John Hickenlooper

JUST WATCHED Hickenlooper talks to CNN about Trump's immigration policies Replay More Videos ... MUST WATCH Hickenlooper talks to CNN about Trump's immigration policies 05:17

Quietly, the governor of Colorado made it to the final cut of Clinton's vice presidential list. He has a powerful story -- small businessman, mayor of Denver, two term governor -- and represents a part of the county where Democrats are growing. But, he is very low-key -- and may be too moderate for Democratic primary voters.

Amy Klobuchar

JUST WATCHED Klobuchar talks about ousted National Security Advisor Michael Flynn Replay More Videos ... MUST WATCH Klobuchar talks about ousted National Security Advisor Michael Flynn 04:15

Klobuchar, who has represented Minnesota since 2006, and is widely seen as both ambitious and talented. But, buzz about Franken is eclipsing her right now.

Mitch Landrieu

JUST WATCHED New Orleans begins Confederate statue removal Replay More Videos ... MUST WATCH New Orleans begins Confederate statue removal 00:52

The mayor of New Orleans -- and scion to a famous political family -- was floated as a possible presidential candidate in the New York Times . Which is something. But hard to see how he gets from here to there.

Seth Moulton

The Massachusetts House member wins rave reviews and is seen by almost everyone as a future Democratic leader. (I had an email exchange with Moulton about the future of the Democratic party back in February .) But 2020 feels, at least at the moment, like too much of a leap.

Martin O'Malley

JUST WATCHED Martin O'Malley suspended his first presidential campaign in 2016 Replay More Videos ... MUST WATCH Martin O'Malley suspended his first presidential campaign in 2016 00:56

O'Malley ran a respectable campaign for president in 2016 and judging by his travel might want to run it back . But it's hard to see how a 2020 bid would be much different than his 2016 run.

No Tier (Rich businesspeople who've never run for anything before)

Mark Cuban

JUST WATCHED Mark Cuban questions Trump's competence Replay More Videos ... MUST WATCH Mark Cuban questions Trump's competence 03:17

The Dallas Mavericks owner has emerged as one of the most vocal -- and effective -- critics of Trump . If he ran, he'd likely bill himself as a Trump 2.0 -- a successful businessman bringing the lessons he's learned in the private sector to public office.

Sheryl Sandberg

JUST WATCHED Sandberg opens up about husband's death (full) Replay More Videos ... MUST WATCH Sandberg opens up about husband's death (full) 08:05

Howard Schultz

JUST WATCHED Starbucks CEO in 2016: Politics is a cloud over U.S. consumers Replay More Videos ... MUST WATCH Starbucks CEO in 2016: Politics is a cloud over U.S. consumers 02:15

The Starbucks founder is clearly interested in influencing public policy going forward -- although it remains to be seen if that means a presidential bid. Schultz has a rags-to-riches story that most people don't know and would almost certainly be appealing.

Mark Zuckerberg

JUST WATCHED Mark Zuckerberg surprises family at dinner Replay More Videos ... MUST WATCH Mark Zuckerberg surprises family at dinner 01:01