Every couple of election cycles, angry voters pick some officeholder to hold responsible for their frustration with taxes and other sins of government.

Cook County Assessor Joe Berrios is doing everything he can to keep from being that somebody in 2018 but finds himself in a tough re-election battle with Fritz Kaegi, a businessman with deep pockets and no prior political experience.

“I think I’m in good shape,” Berrios said Friday at the offices of the Cook County Democratic Party, which he has chaired since 2007.

Berrios, 66, who was elected assessor in 2010 after 22 years on the county Board of Review, said he believes 85 percent of the county’s Democratic ward and township organizations “are sticking with me,” including county board President Toni Preckwinkle, along with many other “friends throughout Cook County and people who believe that I do a fabulous job.”

Cook County Assessor Joe Berrios: “I don’t do taxes. I do assessments. I set assessments on properties.” | Mark Brown / Sun-Times

But some Democratic politicians say Berrios has become the face of taxpayer dissatisfaction, and polls have indicated he could be fighting for survival.

Kaegi has promised to overhaul a “biased, structurally racist, inaccurate system” that under-assesses downtown commercial properties to the detriment of other property owners. He has spent $1.3 million of his own on his campaign, helping match a Berrios warchest built primarily from property tax appeals lawyers.

In an indication of the shifting sands, Ald. Chris Taliaferro (29th) said Friday he’s withdrawing his endorsement of Berrios, in part based on constituents who “wondered why I’m still endorsing Berrios.”

Taliaferro is among several Democratic politicians who say they gave Berrios the benefit of the doubt last summer when the Chicago Tribune reported the assessor was valuing lower-priced homes relatively high and higher-priced homes relatively low, hurting minority homeowners.

They had a change of heart after the Tribune’s findings were backed up last month by the nonprofit Civic Consulting Alliance, which reported failures in the residential assessment system resulted in “a wealth transfer from owners of lower-value homes to those of higher-value homes.”

Berrios must already have looked vulnerable to politicians sizing up his prospects. A decade of mostly self-inflicted bad publicity over ethical matters ranging from hiring family members to rejecting the authority of the county’s inspector general and Ethics Board had damaged his reputation.

Signs of his diminishing influence could be seen in the election defeats of his state-representative daughter and the alderman who’d been his partner in running the 31st Ward Democratic Organization.

Yet no elected official stepped up to challenge Berrios, leaving that to Kaegi, who left his position as a mutual fund manager to run. A third candidate, Andrea Raila, was ruled ineligible. Her name will still be on the ballot, but votes for her won’t count.

Fritz Kaegi. | Rich Hein / Sun-Times

Kaegi talks more like he’s pursuing an interesting job opportunity than the key lever of Chicago political power the office has long been. He says his experience as a chartered financial analyst qualifies him to value assets including real estate — the essence of the assessor’s job.

Kaegi promises to emphasize sales prices of downtown skyscrapers in determining their value for assessment purposes.

“There is no better measure of value than a transaction. Everything else is an estimate, a theory,” said Kaegi, 46, who grew up in Hyde Park and lives in Oak Park with his wife and kids.

Berrios maintains state law requires placing more emphasis on a commercial property’s income than sales price. He said Kaegi’s approach won’t pass muster in court.

In a departure from current practice, Kaegi promises he would make public the methodology used in assessing individual properties, producing a more transparent system that could reduce the need for property owners to hire tax appeals lawyers to lower their assessments — long seen as a corrupting influence.

Berrios suggests he’s a victim of confusion over the assessor’s role. “I don’t do taxes,” he said. “I do assessments. I set assessments on properties. I don’t control the rate.”

Kaegi, who has gone to the trouble of becoming a state certified assessment officer, says he will be happy to explain that it’s the assessor’s job to make sure everyone pays their fair share.