CHICAGO (CBS) — A mad scramble in Illinois politics – veteran Chicago Congressman Luis Gutierrez will not seek reelection.

CBS 2’s Mike Puccinelli has more from outside his Logan Square Office.

A political shocker coming out of Illinois’ Fourth Congressional District. CBS 2 has confirmed that after 25 years on the job, 64-year-old Congressman Luis Gutierrez is stepping down. He is expected to talk about his reasons why in an Tuesday afternoon news conference.

Gutierrez was an ally of Harold Washington in the City Council before he was elected to Congress in 1992. Since then, he has become a national leader on immigration issues and a major champion of his ancestral home in Puerto Rico, traveling there recently in the wake of Hurricane Maria.

He has flirted with retirement years ago only to reconsider at the last minute. This time he even filed nominating petitions on Monday, but is expected to withdraw those submitted signatures.

The congressman appeared at an event Monday afternoon at the Puerto Rico Welcome Center in Humboldt Park. Sources tell CBS 2 Gutierrez has informed Mayor Rahm Emanuel of his decision to call it quits.

There is expected to be a bit of a scramble for a rare open seat in Congress. Gutierrez is expected to support County Board Commissioner Jesus “Chuy” Garcia. Alderman Carlos Ramirez-Rosa is also expected to begin circulating petitions.

“It’s going to be tough, it’s gonna be a bit of a scramble, I’m sure it will happen and it will be the democratic primary that matters the most, it’s a heavily gerrymandered district and it’s an urban district. It’s not the general election we’ll be thinking most about, the democrats are going to have to get themselves lined up quickly,” said.

Anyone seeking to run has about a week to come up with 7,000 signatures required by law to run for Congress in the Fourth District.

The Gutierrez announcement is expected at 1 p.m. Tuesday.

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