A bill that would let voters decide if the officer should be an elected position awaits Rauner's signature. It's a board-appointed post and has been held by Marty Paulson since 2003.
If Rauner signs, a binding question would appear on Nov. 6 ballots in Lake County. The post would be up for election starting in 2020 if voters approve the plan.
The county board voted 14-5 to ask Rauner to use his amendatory veto power to expand the legislation so the same question appears on ballots for the roughly 60 Illinois counties that have board-appointed assessment officers and board-chosen chairmen, just as Lake does.
The assessment officer coordinates property tax assessment activity throughout the county. Proponents of the state legislation have complained about Lake's high property taxes and have said electing the chief assessment officer would give residents more control over those taxes.
Opponents say the bill illegally singles out Lake County. They also say the assessment officer has little control over the amount of property taxes homeowners pay because tax levies are set by local government boards.
Some critics also have complained the plan was rushed through the General Assembly without giving county officials an opportunity to give input.
"It's just the way it got here and how it was done," said county Commissioner Mike Rummel, a Lake Forest Republican.
A crowd of county residents concerned about the issue attended Tuesday's meeting in Waukegan, and they overwhelmingly supported the legislation as written. They included Zion activist Clyde McLemore, who said giving voters the ability to elect the assessment officer "takes control away from this board" and improves government transparency.
The meeting got a little wild when McLemore made an unrelated remark about Commissioner Mary Ross Cunningham of Waukegan, leading to a heated exchange between McLemore and board Chairman Aaron Lawlor in which Lawlor repeatedly told McLemore to sit down.
County commissioners spoke at length on both sides of the issue.
Highland Park Democrat Paul Frank was among those who supported the bill as written.
"I don't think we should be standing in the way of voters," Frank said.
Fox Lake Republican Judy Martini criticized the county resolution, too. Lake County's high property taxes are a problem, Martini said, "and we've got to address that problem."
Joining Frank and Martini in voting against the county resolution were Lake Bluff Democrat Sandy Hart, North Chicago Democrat Vance Wyatt and Grayslake Republican Jeff Werfel.
On the other side, Lincolnshire Republican Ann Maine said she was fine with giving voters the ability to decide whether the assessment officer is elected or appointed. But Maine also criticized the bill for singling out Lake County, and she backed asking Rauner to amend it.
Fox River Grove Republican Michael Danforth was harsher, calling the legislation disingenuous. Electing the assessment officer will not affect property taxes, he said.
"We have the skin of the truth stuffed with a lie," Danforth said. "And that's not a sausage the guy in this chair is going to eat."
A Rauner spokeswoman said the governor is reviewing the legislation but declined to say whether he plans to sign or veto the proposal.
The bill is the third piece of state legislation in the last five years to target Lake County government.
In 2013, the General Assembly stripped election oversight from the county clerk and created a Lake County election commission. A judge declared the law unconstitutional.
Last year, legislators approved a plan to let voters elect the county board's chairman, rather than continuing to have members choose their leader. Rauner vetoed it.