In Illinois, Pete Buttigieg leads the Democratic presidential primary pack in contributions for the first half of the year followed by Bernie Sanders, with a key difference according to a new Chicago Sun-Times analysis: Sanders has an estimated 12,000 more individual donors in Illinois.

Elizabeth Warren comes in third in the Illinois money chase followed by Joe Biden, Kamala Harris and Amy Klobuchar, the Sun-Times study of Federal Election Commission data from the Center for Public Integrity reveals.

The Illinois numbers mirror the national trend when it comes to a new era in campaign fundraising for Democrats ushered in by Sanders and Warren.

The senators from Vermont and Massachusetts, with strong grass-and-net-roots appeal, rely on smaller-dollar online fundraising and get strong results. They do not hold fundraising events. They don’t woo big donors in private meetings.

For the first time, a full picture of presidential donor giving in Illinois is possible because small contributions reported to the FEC through ActBlue, the online Democratic donation service, can be combined with information disclosed on presidential campaign FEC filings on people giving at least $200.

Donations made to a campaign using ActBlue as a conduit count as individual contributors.

The data yield an estimate of how many unique donors in Illinois each candidate has, based on first and last names and ZIP codes reported to the FEC. It’s an estimate because if the names do not have an exact match — say someone uses a middle initial or maiden or nickname one time and not another — the person shows up as different donors.

Of the top “Illinois Six,” Sanders and Warren have each made only one campaign stop in Chicago, where they have held big, free rallies open to the public.

The others have been in Chicago often to fundraise because the city has plenty of Democrats who make major donations — and like face time with a candidate at a fundraiser.

The numbers below reflect fundraising through June 30. New data from the FEC for the quarter ending on Sept. 30 is not yet available.

Buttigieg, the South Bend, Indiana, mayor, has collected $1,830,235 through June 30 from an estimated 20,078 donors.

Buttigieg, with a branch presidential campaign headquarters in the South Loop, has headlined many fundraisers in Chicago. Buttigieg is no stranger to Chicago — he was an NBC 5 Chicago intern in 2003.

He’s the only one who successfully straddles the big and small donor worlds.

People who were major Obama “bundlers” are fundraising for Buttigieg. A bundler raises massive amounts of campaign cash by tapping into personal donor networks. Bundlers are valuable because federal law limits an individual donor to giving $2,800 per election, or up to $5,600 for both the primary and general elections.

Buttigieg returns to Chicago on Oct. 18 for a fundraiser with the co-hosts — according to an invitation obtained by the Sun-Times — including Democratic mega donor Dan Tierney of Wicklow Capital; banker David Jacobson, an Obama ambassador to Canada and a leader of Obama’s 2008 finance team; longtime activist Susan Manilow; attorney and former City Hall Corporation Counsel Steve Patton; author Judy Pomeranz; attorney Daniel Siegel; Sarah Siegel, executive at the Box and Ann Thompson, senior vice president at Related Midwest Architecture.

Tickets range from $500 to $2,800.

Sanders, the Vermont senator, took in $1,396,308 from an estimated 32,114 donors. About $1 million was from smaller contributions.

Warren, the Massachusetts senator, collected $823,667 from an estimated 17,591 donors.

Biden, the former vice president whose frontrunner status is being challenged by Warren, got $724,391 from an estimated 9,395 donors. Biden did three high-dollar fundraisers in Chicago last Sept. 19.

Cory Booker, the New Jersey senator, gathered $213,810 from an estimated 3,151 donors. Booker has a fundraiser in Highland Park on Oct. 17 with the tab from $250 to $2,800. Hosts include activists Dana Gordon and Steve Sheffey.

Tulsi Gabbard, the Hawaii congresswoman, reported $133,766 from 3,119 estimated donors.

Entrepreneur Andrew Yang produced $133,295 and has sparked some interest since he has an estimated 5,049 Illinois donors.

Data analysis by the Chicago Sun-Times’ Andy Boyle using FEC data from the Center for Public Integrity.

THE NUMBERS

Total money raised per presidential candidate in Illinois, through June 30, 2019

Pete Buttigieg - $1,830,235.32

Bernie Sanders - $1,396,308.74

Elizabeth Warren - $823,667.54

Joe Biden - $724,391.79

Kamala Harris - $564,025.63

Amy Klobuchar - $402,332.82

Beto O’Rourke - $304,005.67

Cory Booker - $213,810.44

Kirsten Gillibrand - $196,369.34

Tulsi Gabbard - $133,776.61

Andrew Yang - $133,295.61

John Hickenlooper - $90,154.48

Julián Castro - $87,102.16

Jay Inslee - $86,362.15

Marianne Williamson - $60,945.11

Steve Bullock - $59,511.21

Michael Bennet - $57,727.84

Seth Moulton - $44,062.44

John Delaney - $23,827.78

Tim Ryan - $15,075.00

Mike Gravel - $9,920.58

Bill de Blasio - $4,209.00

Joe Sestak - $165.00

Total estimated* number of donations per candidate in Illinois through June 30, 2019:

Bernie Sanders - 32,114

Pete Buttigieg - 20,078

Elizabeth Warren - 17,591

Joe Biden - 9,395

Kamala Harris - 8,995

Andrew Yang - 5,049

Beto O’Rourke - 4,702

Julián Castro - 3,711

Cory Booker - 3,151

Tulsi Gabbard - 3,119

Kirsten Gillibrand - 2,802

Amy Klobuchar - 2,546

Mike Gravel - 2,226

Marianne Williamson - 2,184

Jay Inslee - 1,913

Michael Bennet - 750

Steve Bullock - 463

Tim Ryan - 329

Seth Moulton - 325

John Hickenlooper - 315

John Delaney - 219

Bill de Blasio - 20

Joe Sestak - 5

*Note: Why is this an estimate? The estimate of how many unique donors in Illinois each candidate has is based on first and last names and Zip codes reported to the FEC. It’s an estimate because if the names do not have an exact match — say someone uses a middle initial or maiden or nickname one time and not another — the person shows up as different donors.

SOURCES: Chicago Sun-Times data analysis by Andy Boyle using Federal Election Commission data from the Center for Public Integrity.

Editor’s Note: In an earlier version of the story posted online, the source of data analyzed by the Sun-Times should have been identified as the Center for Public Integrity.