Sen. Ted Cruz’s unyielding opposition to the Affordable Care Act and his willingness to publicly take the fight to fellow Republicans helped cause a brief government shutdown four years ago. But now, with a Republican in the White House and repeal legislation working its way through Congress, the Texas Republican is keeping a low profile, putting his head down and working back rooms to influence the legislation.

Cruz has expressed serious concerns about the bill, the American Health Care Act, released by House Republicans this week and approved by two committees Thursday. His fellow Senate conservatives Rand Paul and Mike Lee have railed against it publicly – Paul dubbed it “Obamacare Lite” and Lee said it was a “step in the wrong direction.” The two joined members of the conservative House Freedom Caucus at a press conference Tuesday to amplify their opposition.

But while Cruz shares the same concerns, he was absent from that press conference, and has not been nearly as vocal in his criticism as his House or Senate colleagues. When a reporter asked if he agreed with the “Obamacare Lite” label, Cruz responded: “I’m not interested in labels; I’m interested in substance.”

He has said he doesn’t believe the bill as written in the House can pass the Senate, but insisted he’s working to push it in a more conservative direction.

“I’m working hard to have these conversations with leaders in both houses and the administration rather than to litigate every one of these details in public,” Cruz told reporters Thursday after a meeting with a handful of GOP senators in Majority Leader Mitch McConnell’s office. “I am hopeful we can get the job done, and that is my objective."

It’s a notable departure from the Cruz of the Obama administration. As a candidate in 2012, Cruz promised to “throw my body in front of a train” to stop anything but a full repeal. Once in the Senate, he waged an 18-hour filibuster over the health care law and pushed so aggressively for defunding it in 2013 that the government shut down, against the wishes of many fellow Republicans. But with President Trump in the oval office, Cruz said his approach needs to change, calling it a “very different environment.”

“Barack Obama did not care what Congress had to say and did not listen to us. The only way to combat Obama was in the public arena,” Cruz said Thursday. “With a Republican president and an administration that wants to solve this problem, there is a lot of room for us to work together productively."

Cruz may take a much more public role next week. The outside group FreedomWorks, which blasted the bill as “Obamacare Lite” and plans a six-figure ad blitz pushing for a full repeal, is hosting a grassroots rally on Capitol Hill next week featuring an address from Cruz.

But for now, he’s pressing his case behind closed doors. Cruz met privately with Vice President Mike Pence Wednesday – Pence posted a photo of the two on Twitter – before bringing his family to the White House for dinner with Trump.

Welcomed @SenTedCruz to my office in the @WhiteHouse. Looking forward to working closely with the Senator on important legislation ahead. pic.twitter.com/F8stH4k1iR — Vice President Pence (@VP) March 8, 2017

Cruz said Melania Trump read his daughters a children’s book before they took a picture with the president, and added that one of his daughter’s had her kindergarten class’s stuffed giraffe in the picture, calling it a personal highlight.

But he was reluctant to share details about the policy substance of either meeting, saying of the dinner with Trump: “The president and I had a far-ranging and I believe a very productive conversation on Obamacare and a number of other topics."

For Cruz, there are both policy and political considerations to factor into his approach to Obamacare. Since fighting Trump aggressively during the presidential primary, Cruz has attempted to forge a relationship with the White House early in the administration. And unlike his conservative colleagues Paul and Lee, who were re-elected easily last year, Cruz is up for re-election next year. The success of the Obamacare debate will be a major factor in his campaign.

Cruz hasn’t shied away from his concerns with the legislation. He takes issue with the structure of tax credits included to help people afford insurance, saying he doesn’t think “creating new entitlements is the right approach.” He said the Medicaid expansion should freeze enrollment immediately, not in 2020 as is currently written. And he advocated for a block grant approach to Medicaid, rather than the per capita allotment in the House legislation.

“With respect to Medicaid, I think the House bill makes meaningful progress on reforming Medicaid, but I think we need to do a lot more,” he said.

But as to how all of these issues can be fixed to earn his support, he mostly demurred, stressing that each of those components, and others, are “among the many topics that will continue to be debated vigorously.”

Cruz has also advocated a more aggressive approach. Republicans are repealing and replacing key portions of the law using the obscure budget reconciliation process that limits what can be included at the behest of the Senate parliamentarian. But Cruz has argued on procedural grounds that stricter conservative policies can be included and that ultimately Pence, presiding over the Senate, would make those decisions. He wouldn’t say if he’d made that case to Trump, Pence or McConnell, but said he’d raised it with “anyone who will listen.”

Throughout the week, he has continually referred reporters to an op-ed he wrote in Politico laying out his goals for repeal. Some in the Senate have noticed Cruz making an effort to be productive behind the scenes.

“I think he spoke at lunch about his desire to get to yes on the health care bill, which is very constructive,” Sen. John Cornyn, Cruz’s Texas colleague and the GOP whip, told RCP Wednesday.

Said one GOP strategist of Cruz’s more muted approach: “It’s different, but maybe it’s an encouraging sign of what’s to come. Maybe he’s going to operate differently in the new world.”

Cruz has repeatedly suggested this week that while there are concerns about the legislation, “failure is not an option,” pointing out recent elections, including 2016, when repeal and replace was a key Republican promise. His own re-election in 2018 may depend on Republicans’ ability to fulfill that promise.

“I think it’s important that we get it right, and I spent much of yesterday having very productive conversations with senators, House members and multiple leaders in the administration about how we get the job done,” Cruz said. “The House bill that’s currently drafted I don’t believe will pass the Senate, but I believe we can fix it.”