This should be Luis Gutierrez’ time to shine in the spotlight. Two of his top issues, Puerto Rico and immigration, have been front and center all year in the national media. Democrats think they have a real chance at winning back control of the House, and the Chicago congressman’s 12 terms in office would put him in line for a chair if they do. He has a solidly Democratic district and the ability to make news whenever he wants, and at 63 years old has plenty of time to increase his political strength.

Thus his filing for re-election on Monday came as no surprise — but his sudden decision to retire does:

Signaling the end to a quarter century career in Congress, Rep. Luis Gutierrez will announce Tuesday that he will not seek re-election, Democratic sources tell the Chicago Sun-Times.

The Northwest Side Democrat has been one of the more high-profile Latino politicians in the country, advocating forcefully for immigrant rights, since he became a U.S. representative 25 years ago. …

The sources added that Cook County Commissioner Jesus “Chuy” Garcia, D-Chicago, likely will run to succeed Gutierrez in next year’s election with Gutierrez’s endorsement. The sources said 22nd Ward Ald. Ricardo Muñoz was expected to run to replace Garcia on the Cook County Board of Commissioners.

Gutierrez and Garcia are scheduled to appear at a campaign kickoff event for Garcia at Mi Tierra restaurant in Little Village — Garcia’s neighborhood — at 6 p.m. Tuesday.

As Politico notes, Gutierrez changed his mind in a hurry:

Gutierrez, who has held his seat since 1993, is expected to announce Tuesday afternoon he’s withdrawing the nominating petitions he just filed on Monday and will formally endorse Jesus “Chuy” Garcia.

Garcia, a Cook County commissioner, had forced Mayor Rahm Emanuel into a runoff election in 2015. His bid for Gutierrez’s seat means Garcia will not challenge Emanuel again in 2019 as he had previously planned, sources tell POLITICO. With petition filing open on Monday, candidates for Gutierrez’s open seat will have to turn in nearly 7,000 signatures in less than a week.

Sources say discussions between Garcia and Gutierrez began Friday. Two Democratic sources said that polling already had been done in the district and showed Garcia with a strong lead among possible opponents.

Garcia’s political strength almost certainly has nothing to do with this. Democrats have a +33 edge in IL-04, and Republicans didn’t even bother to run a candidate against Gutierrez last November. In 2014, a strong Republican midterm, Gutierrez won 78/22. He managed to eke out a 77/14 win in the GOP tidal wave of 2010, too. This was as safe a seat for Gutierrez as possible; he could have hung on for another twenty years without even breaking a sweat.

So why did Gutierrez suddenly change his mind? Three possible scenarios. The first is the most prosaic — he may simply have gotten tired of the job. He’s been in Congress since the Clintons first arrived in Washington DC and managed to outlast them. Retirement from Congress is hardly an unusual event, but it’s very strange to make that decision just hours after filing for re-election in a super-safe district. That’s a hint that something else drove the decision.

Second scenario: Gutierrez made a deal to help out Rahm Emanuel win re-election. That’s also not an unknown scenario, where political parties look for ways to extend the status quo by reshuffling the players. Where this seems weak is why Democrats would care enough to push out a senior member like Gutierrez to help out Emanuel when Democrats will control the mayoral office no matter who runs and wins. It might be more of a personal favor by Gutierrez, but that doesn’t make a lot of sense either; they may be tight friends (if they are at all), but giving up a safe seat and a national platform just to help out a buddy from a predicament of his own making seems generous to the extreme, unless the quid for the quo turns out to be fabulous. That wouldn’t come from a mayoral level of patronage, but perhaps Democratic lobbyists have something else in mind.

Third scenario: A big shoe is about to drop on Gutierrez and he wants out before it does. That’s the scenario that right-leaning social media seems to like best, but there’s absolutely nothing behind it other than sheer speculation … at least for now. With settlements getting exposed and victims speaking out, no one knows who might be next on the hot seat except the senators and representatives who have been protected by the secrecy cloak of the Office of Compliance. Every unexpected retirement will get viewed through this prism, whether warranted or not.

Of all the speculation about Gutierrez’ motives and those of other Capitol Hill denizens opting for retirement this cycle, this is the most unfair — but who’s fault is it that the OOC cloak exists in the first place? They made their bed on credibility and benefit of the doubt, almost literally, and now they have to lie in it.

As for me, I’m betting on a Scenario Two tradeoff, with a souçon of Scenario One. Gutierrez may be looking for a change of scenery and willing to do the Chicago Machine a solid on his way out. They’ll be sure to do a solid in return, either up front or soon enough. If it’s anything else, we won’t have to wait too long to find out.