An office in a South Loop building is the national home of Democratic presidential contender Peter Buttigieg’s political and communications operations, the key branch office of a campaign headquartered in South Bend.

Buttigieg, the South Bend mayor, established the Chicago outpost to be closer to Midway and O’Hare airports. South Bend is only a $14.25 and two-hour-plus South Shore Line ride away, with the proximity central to making the arrangement work.

Buttigieg, who is in Chicago for fundraising often since launching his campaign, returns Tuesday for two events, one low dollar — the tab starts at $25 — and the other with a $500 minimum.

The open-concept loft-like, brick-walled space, near the Trader Joe’s at Roosevelt Road, is used by about 30 staffers at present, with plenty of room for expansion. The branch also houses several staffers with fundraising duties; the campaign prefers referring to these workers as the “investment team.”

One of the latest additions to the growing Buttigieg campaign in Chicago is veteran Chicago-based Democratic strategist Hari Sevugan, who earlier this month became the deputy campaign manager. Sevugan, was a partner in 270 Strategies’ Chicago HQ, with the consulting firm spawned by former Obama campaign staffers.

Sevugan was a senior spokesman in former President Barack Obama’s 2008 campaign. Obama based his 2008 and 2012 campaigns in high rise office towers, both off Michigan Avenue near Randolph Street.

Other key players in the Buttegieg Chicago outpost:

*National Political Director Stephen Brokaw, also a principal at 270 Strategies who worked on both of the Obama presidential campaigns.

*Sean Savett, the rapid response communications director, who stepped down as the deputy communications director based in Washington for Sen. Tammy Duckworth, D-Ill.

*National Press Secretary Chris Meagher, who came to Chicago at the end of January to handle communications for Cook County Board President Toni Preckwinkle’s mayoral bid.

*Leah Israel, a Buttigieg fundraising consultant who continues to handle Duckworth fundraising duties.

BUTTIGIEG OFFICE IN SPACE JUST VACATED BY OBAMA POLITICAL GROUP

The Buttigieg team moved in June 6, with one Democratic political organization taking the space vacated by another: Organizing for Action, an outgrowth of Obama’s 2008 Obama for America campaign.

OFA, at one time based in the West Loop, didn’t, in the Obama post-presidency, have the purposes it had while he was in office. So OFA combined with the anti-gerrymandering group helmed by Obama’s attorney general, Eric Holder.

Obama has made redistricting one of his priority “causes.”

WARREN SINKS ROOTS IN ILLINOIS

With an eye on the March Illinois primary — early enough to make a big difference — Dem presidential hopeful Sen. Elizabeth Warren, D-Mass., is the first to establish an Illinois political organization.

Her team recently hired Steve Campbell to be her Illinois state director. Campbell was the political director for the Democratic state senate political shop overseen by Illinois Senate President John Cullerton, D-Chicago.

Warren also picked up the endorsements of Illinois State Treasurer Mike Frerichs and Daniel Biss, a former state senator who ran for governor.

Though Buttigieg has a Chicago office, he has yet to put together an Illinois political team.

KLOBUCHAR TEAM KICKS OFF ILLINOIS DELEGATE ORGANIZING

Early organizing can mean a lot when it comes to actually putting together delegate slates, a complicated process with lots of rules to make sure the delegates are diverse and gender equal.

With so many Democrats running for president — if 10 candidates survive through the March Illinois primary — there will be a combined number of more than 1,000 delegates on ballots.

In 2020, Illinois will have 184 delegates and 13 alternate delegates at the nominating convention in Milwaukee.

On Thursday, the team for presidential hopeful Sen. Amy Klobuchar, D-Minn., held its first meeting to start to put together delegate slates in the Chicago office of one of her campaign consultants, Pete Giangreco.

Observed Giangreco, putting together full slates — crucial to actually winning the nomination — is a “test” of the ability of a presidential campaign to organize.