His voice somber, Republican Gov. Bruce Rauner on Thursday shocked many on both sides of the aisle when he signed into law a measure to expand taxpayer funding of abortions and ensure the procedure remains legal in Illinois.

The governor made the announcement at a Chicago news conference, prompting cheers from the women’s rights advocates flanking him and smiles and applause from a watching first lady Diana Rauner.

Just as quickly it also sparked outrage from many anti-abortion Republicans, who accused the governor of broken promises, betrayal and lies.

The decision was especially surprising after the governor’s recruitment early this year of new top advisors, including Kristina Rasmussen and Michael Lucci, both former members of the conservative think tank the Illinois Policy Institute.

But Rauner suggested none should be surprised.

“I am announcing that I am signing House Bill 40,” Rauner said. “I am being true to my values and my views. I have always been true to those. … I have to make a decision. I have to do what I believe is right for the people of Illinois. And I have to be consistent with my values.”

The bill ensures abortion remains legal in Illinois even if the U.S. Supreme Court overturns Roe v. Wade, while also allowing women with Medicaid and state-employee health insurance to use their coverage for abortions. Opponents of the bill, however, have argued that abortions wouldn’t be made illegal in the state even if Roe was overturned, and the bill was always really about expanding insurance coverage.

The signing of HB-40 seemed impossible in April, when Rauner said he wouldn’t support it because of “sharp divisions of opinion of taxpayer funding of abortion.” That sparked months of campaigns by gubernatorial candidates and abortion rights groups, who argued the moderate governor was going back on his word that he did not have a social agenda. Personal PAC, an abortion rights group, also targeted the first lady, calling both Rauners liars over a candidate questionnaire Bruce Rauner signed touting his own support for women’s reproductive rights.

First lady Diana Rauner smiles and applauds from the back of the room as Gov. Bruce Rauner announces he will sign abortion legislation HB40. | Ashlee Rezin/Sun-Times

But Rauner on Thursday said he’s the same person he said he was back in 2014 when he ran for governor.

“I personally am pro-choice. I always have been. And I made no qualms about that when I was elected governor. And I have not and never will change my views,” Rauner said. “I personally believe that a woman should have, must have, the right to decide what goes on in her own body.”

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He also touted the bill’s efforts to give low-income women access to abortions, arguing “no woman should be forced to make a different decision than another woman makes purely based on her income.”

The decision was a shock to many, including legislators who sponsored the measure. Sources said Rauner announced his decision in an unorthodox fashion. There were no calls to sponsors. There were no courtesy calls to legislators who opposed the measure.

A source with close knowledge of the legislation said the Rauners were both briefed on the bill on Tuesday. On Wednesday, both met with prominent Republicans, who were told that the governor was still deciding what to do.

A final decision, sources said, appeared to have been made on Thursday morning.

After speaking at an Illinois Chamber of Commerce luncheon, in which Rauner delivered a spirited campaign-like speech about his plans to reform the state and his excitement about the U.S. Supreme Court announcing they’d hear a union fee case he first filed, the governor told reporters he’d announce his decision on the controversial legislation within hours.

There was no fanfare regarding the actual signing of the bill. The governor did so privately, shortly after his news conference, with no invitations for the bill’s sponsors to attend.

Sponsor state Rep. Sara Feigenholtz, D-Chicago, said she was “grateful” that the governor “has finally realized how important this legislation is to women in the current political climate.” She noted he “decided to stick to his original promise.”

Former Lt. Gov. Corinnne Wood speaks at Thursday’s news conference. Sun-Times Media.

While former GOP lieutenant governor Corinne Wood stood alongside the governor, Rauner’s own lieutenant governor — and perceived running mate in next year’s election — issued a statement saying she disagrees with his decision as a “pro-life Republican.” She called the Democratic-sponsored bill a “political ploy to divide the people of Illinois.”

Illinois House Republican Leader Jim Durkin said he was “displeased” with the decision, but urged unity within the GOP.

House Republican Floor Leader Peter Breen, R-Lombard, called Rauner’s decision “a betrayal.”

“In politics you are only as good as your word,” Breen said, while warning that it is “inevitable” that Rauner will now face a Republican primary challenger in March.

“It’s not that hard to get on the ballot to be governor when you’ve got this kind of groundswell of opposition that I believe is going to be mounting here in the next few days,” Breen said.

House Republican Floor Leader Peter Breen talks to reporters,  criticizing Gov. Bruce Rauner for announcing he will sign the abortion legislation HB-40 at the Thompson Center Thursday, Sept. 29, 2017. | Ashlee Rezin/Sun-Times

Breen said he won’t support the governor, and expected the same response from many of his colleagues.

“When you look someone in the eye and shake their hand and tell them you’re going to do something and then you reverse course, that’s a broken commitment,” Breen said. “As I understand it he made that commitment to the Cardinal Archbishop of Chicago. I know even the most corrupt Chicago machine politicians think twice before lying to a priest,” Breen said.

Cardinal Blase Cupich tweeted that “Gov. Rauner has signed into law a very disturbing bill he once promised to veto.”

The harsh reaction from some Republicans, Rauner’s somber tone — and the rough summer the governor has had — left some speculating whether he will run for re-election.

Asked Thursday morning whether he still planned to seek a second term — before he had announced his plans to sign the bill — the governor laughed off the question.

“I’ll be talking about that soon,” the governor said with a chuckle.

Illinois Republican Party Chairman Tim Schneider said he was disappointed with the signing, but tried to pin the blame on a popular target: House Speaker Mike Madigan.

Schneider said that Madigan and Democrats are trying to divide the party “and elect a Madigan-backed candidate for governor.”

“As Chairman of the Illinois Republican Party, I will not let that happen,” Schneider said. “There is no daylight between Governor Rauner and the Illinois Republican Party and we will continue working hard to ensure his reelection and finally defeat Mike Madigan once and for all.”