IL-4 · House

The district, in brief

Illinois's 4th district is based in southwest Chicago, including Brighton Park, Gage Park, Garfield Ridge, South Lawndale and West Lawn, and the western suburbs of Cicero and Berwyn. The lines are the map first used in 2022; the district was not redrawn.

The seat is open. Incumbent Democrat Chuy García, last elected with 67.5%, filed for another term and then withdrew after the filing deadline, citing health reasons, leaving only his chief of staff, Patty Garcia (no relation), on the Democratic primary ballot; she took 52,616 votes unopposed. David Axelrod called the move machine tactics, and the House passed Marie Gluesenkamp Perez's motion of disapproval 238-186 over Hakeem Jeffries's objection. The Republican nominee is Lupe Castillo, a pharmacy technician who ran in 2024 and was unopposed with 8,336 votes. Independents on the ballot are Chris Getty, mayor of Lyons, and Lindsay Church; Getty, Mayra Macías and Byron Sigcho-Lopez are Democrats who ran as independents in response to García's actions, and the latter two failed to qualify. Ed Hershey of the Working Class Party is also standing. As of April 25, 2026 Patty Garcia had raised $270,042 with $195,352 on hand; the other four report $0.

Decision Desk HQ (July 14, 2026), the Cook Political Report (February 6, 2025), Inside Elections (December 5, 2025) and Sabato's Crystal Ball (July 15, 2025) all rate the seat D. One district poll is recorded: the Independent Center Voice Poll sponsored by the Bullfinch Group (July 31 – August 1, 2026, 653 RV) had Garcia 34%, Castillo 15%, Getty 9%, Hershey 4%, undecided 37%.

A paragraph quoting a model forecast from the day this brief was written is omitted; the current forecast is at the top of this page.

The facts, each beside its sentence

Not in the source: The text gives no presidential result for the district.; The model's basis says no district polls, but the text lists one general-election poll (Independent Center Voice Poll, July 31 – August 1, 2026).; Ed Hershey (Working Class Party) is on the ballot in the text but not in the facts' candidate list.; The text does not say which year García was last elected (it says only 'last elected with 67.5%').; Ratings are given only as 'D' with no Lean/Likely/Safe gradation.; No endorsements are listed; the endorsement sections are empty.

Read from the district's section of Wikipedia's state page (CC BY-SA), archived as 30ccfd4a5fb3; written by claude-fable-5-1 (batch reader) on 2026-09-30 and checked mechanically: every quote occurs verbatim in the archived text, every number in the brief occurs in the inputs. No probability here is the reader's.

Who holds the seat now

Jesús G. "Chuy" García (Democrat), in this chamber since 2019, 4 terms. Committees: House Committee on Transportation and Infrastructure; House Committee on the Judiciary.

From the congress-legislators dataset (CC0), archived as ae8cb9477c48. For a Senate race this lists both of the state's senators; the one whose term ends in the election year holds the seat on the ballot. For a House district redrawn for 2026 it is the member elected under the old lines with this number, who may be running elsewhere; the dossier above names who is running here.

How it has voted for president

A shift of 13.2 points toward the Republicans from 2016 to 2024. county returns placed on the current lines by 2020 block population; MEDSL county file (2016), an MIT-licensed county file (2020, checked against certified state results) and MEDSL precinct returns (2024). For a district split across counties this is an estimate, and where the state published the exact 2024 figure for these lines, that exact figure is the one the model uses.

Who are the voters?

Of about 481,221 adults 25 and over. In 2020 the district voted 73.6% Democratic (two-party) for president. With the same preferences and a 2022-style midterm turnout, it would vote 72.6% Democratic: the midterm electorate alone moves the margin 2.1 points toward Republicans. Group shares are estimated from how results vary across the state's census tracts (ecological inference, anchored to Pew's 2020 validated-voter figures) and calibrated to this district's actual 2020 vote; turnout is the Census survey's state rate by race and national rate by education, whose state samples carry margins of several points.

Not answered here: how each group will vote in 2026. These are 2020 preferences; this profile is description, not yet an input to the forecast.

The money

FEC bulk candidate summaries through June 30, 2026; no independent expenditures reported for or against any candidate, which usually means nobody outside the district thinks it is in play.

The district in numbers

ACS 5-year 2023, the Census Bureau's own tabulation of this district (118th Congress lines). Unemployment is the BLS county series placed on the district by block population, not seasonally adjusted, so changes are same-month comparisons. Income, transfers and jobs are BEA county accounts placed the same way, compared with the average district. Every other figure is a named column of a named table in the Bureau's summary file, archived before it was read. This is what a reader knows about a district before looking at a poll; the model does not yet use it, and whether it should is a registered question.

Who is favoured, and by how much?

The 90% interval runs from +11.8 to +41.9 points, D-R. It is wide because this district has never been polled.

What is this built on?

A model trained on every contested House race 2012-2024 predicts this district's lean from its own record: presidential and House results on the current lines, incumbency, both candidates' prior offices, outside and party money before 1 October, demographics and public-assistance shares from the Census release before the election, local unemployment and income, and religious tradition. The national margin comes from presidential approval, the economy, the midterm penalty and the generic ballot corrected for its measured lean. Draws share national and state errors, so the seat total and this district come from the same simulation.

Not answered here: district polls, which are not yet folded in.

Why does the model say this?

Each figure is how far this district's predicted lean moves when that one feature is set to the typical value across 2026 districts, everything else held: 2024 presidential lean (D+30.7): 20.6 pts toward the Democrat; PAC money balance: 8.9 pts toward the Democrat; 2024 House lean (D+45.1): 5.5 pts toward the Democrat; moved from other state share (0.5%): 2.3 pts toward the Republican; presidential trend 2020-24 (R+12.0): 1.6 pts toward the Democrat.

How sure is it, and of what?

Total sd 9.08 points, made of the seat's own volatility 90%, correlated polling error 10%. The decomposition is stored with the forecast rather than reconstructed, so a probability whose dominant input is a placeholder is visibly that.

Not answered here: a nowcast. 'If ballots were cast today' needs something that observes today, and for a House district nothing does. Publishing the election-day figure under both labels would make one forecast look like two.

How was this number made?

Run 6f211e6f-2bdc-4dda-8f72-81fc628dab0b, house_district_prior/0.2.0, as of 2026-10-02. Promoted by a pre-registered gate: on 2016-2022 its Brier score was 0.036 against 0.049 for the previous method, and on a single 2024 run 0.023 against 0.032 (experiments/district_gate_result.md, with an independent review).