In 2019, Sigcho-Lopez was elected to succeed outgoing 25th Ward alderman Danny Solis.
On April 10, 2019, prior to being sworn in, Sigcho-Lopez joined six other newly elected members of the City Council in protesting against the approval of tax increment financing for the Lincoln Yards and The 78 real estate developments.[7]
Sigcho-Lopez assumed office May 20, 2019.
On June 12, 2019, Sigcho-Lopez demanded a review of all permits and licenses approved by disgraced former Alderman Danny Solis.[8]
In November 2019, Sigcho-Lopez was one of eleven aldermen to vote against Mayor Lori Lightfoot's first budget.[9] He joined all five other members of the Socialist Caucus in signing a letter to Lightfoot which criticized her budget for "an over-reliance on property taxes" and "regressive funding models" that are "burdensome to our working-class citizens, while giving the wealthy and large corporations a pass."[10] Sigcho-Lopez, over the course of Lightfoot's mayoralty, would be regarded to be a vocal critic of her.[11]
On March 22, 2024, Sigcho-Lopez spoke at a City Hall rally against the Israel–Hamas war where Marine veteran Zachary Kam had burned a flag that he had flown while on tour in Afghanistan, prompting some of Sigcho-Lopez's City Council colleagues to call for him step down as chairman of the Council's Housing Committee.[12] On April 1, 2024, a resolution to remove him as chair failed 29 to 16.[13]
Personal life
Sigcho-Lopez is married to Loreen Targos. In June 2022, Sigcho-Lopez and Targos became parents to triplets.[14]