Last week, the Cook County Democratic Party pledged its support to Democratic candidate J.B. Pritzker, marking yet another key endorsement of the 2018 race for Illinois governor.

The endorsement comes several months after 17 union endorsements for Pritzker in May and June, siphoning coveted labor backing from fellow Democrats Chris Kennedy, Ameya Pawar, and Daniel Biss a full 10 months ahead of the March 20 primary.

Taken together, these endorsements solidify Pritzker’s spot as an early frontrunner in the race. But are they unprecedented?

At first glance, yes. For instance, the AFL-CIO, one of the largest unions in the state, has never endorsed a primary candidate prior to December of the year before an election—until now. But the union’s early leap into the 2018 race is also indicative of broader patterns shaping the Illinois governor’s race over the past decade and a half.

Based on interviews and an analysis of news reports spanning from the 2002 gubernatorial election until today, Chicago found that primary endorsements have slowly begun to pull away from the fall and winter months preceding the election, instead moving toward the summer months of May through August. Removing the outlying earliest endorsement each cycle, it's clear the bulk of endorsements are coming earlier and earlier each election. (See the data below; some dates are approximate.)

During the 2002 election cycle, for instance, the earliest major endorsement came from sitting Governor George Ryan for Republican candidate Jim Ryan in late August 2001, with the remaining 12 endorsements falling between October 2001 and February 2002. But by the 2014 election, at least five endorsements were made during July and August of the year before.

According to Illinois political experts, the shift represents a gradual lengthening of campaigns flowing down from the national to state level.

“It’s part of a continuing pattern for the last several decades,” says Dick Simpson, a political science professor at the University of Illinois-Chicago and a former Chicago alderman. “Presidential campaigns have been run at least two and usually four years in advance of the election. Gubernatorial elections have been gearing up, but not as early as this particular cycle has been with so many candidates.”

To some extent, a crowded Democratic field is circumstantial: This is the first race without an incumbent Democratic governor since 2002, when Republican George Ryan chose not to run for reelection in wake of federal investigations into his tenure as Illinois secretary of state. Yet Democrat Rod Blagojevich, who won the 2002 election, did not announce his candidacy until July 2001. By comparison, Pawar, Kennedy, Biss, and Pritzker hopped into the 2018 race in January, February, March, and April 2017, respectively.

Simpson says that their early entry is mostly linked to a desire to build capital through long-term fundraising. Current Gov. Bruce Rauner, who spent a record-breaking $65.3 million on his 2014 run for the governor’s seat, is reported to have close to $1 billion in assets.

“One of the problems has been that you have to raise more and more money,” Simpson says. “Previously, gubernatorial campaigns cost about $20 million. It looks like several of the candidates will have upwards of $50 million this time.”

Pritzker, who has an estimated net worth of $3.4 billion, is widely believed to have the best chance of competing with Rauner’s campaign funds—a valuable asset in a race that’s already shaping up to be the priciest in Illinois history. This May, Rauner received a record-setting $20 million donation from hedge fund owner (and Illinois’s richest individual) Ken Griffin; as of June, Pritzker self-funded $14 million worth of campaign contributions.

“There’s an establishment feel that Pritzker is good for Democrats in that he’s got the money. [The unions are] savvy; they’re not just wide-eyed neophytes,” says Christopher Mooney, a researcher at the Institute for Government and Public Affairs. “They’re making strategic decisions.”

And as increasingly wealthier candidates continue to pile in, Mooney says that the governor’s race will grow longer—and with the increased length, early endorsements seem bound to continue.  

“There’s a feeling that if you get in too late, all the donors, all the available endorsements will already be gone,” Mooney says.