President Obama has nominated Andrew M. Slavitt to helm the Centers for Medicare and Medicaid Services, setting the stage for heated grilling by Republican legislators at confirmation hearings.

The White House announced the nomination of Slavitt, who is better known as “Andy” and has been CMS’s acting administrator since Marilyn Tavenner’s resignation last winter, on July 9.

Slavitt is well known in healthcare and Beltway circles as the former government contractor who worked on the glitchy HealthCare.gov website before being hired by CMS to fix what was broken with the site right from its rollout.

Capitol Hill Republicans were not slow to voice objections. Senate Majority Leader Mitch McConnell tied Slavitt to the Affordable Care Act as a whole.

“The head of the agency that oversees Medicare and Medicaid should be focused on what the American people expect him to do: administer these important programs, not allow his attention to be diverted instead to the implementation of some gigantic, unworkable health care law that hurts hardworking Americans,” McConnell said in a statement. “The sole focus of CMS should be to look out for our nation’s seniors and the many vulnerable Americans who use these programs, without the distraction of Obamacare.”

This was consistent with misgivings previously expressed over Slavitt by GOP lawmakers.

In April, Senate finance committee chairman Orrin Hatch (R-Utah) and Senate judiciary chairman Chuck Grassley (R-Iowa) sent a letter to HHS Secretary Sylvia Matthews Burwell raising red flags over possible cronyism and conflicts of interest, as Slavitt’s last private employer was Optum, a subsidiary of UnitedHealth Group. The two cited a separate letter they’d sent the prior year, when CMS first hired Slavitt, and complained that CMS’s response had not provided “sufficient information to relieve our concerns.”

The battle lines are thus drawn, as the White House announced the nomination—albeit in a relatively low-key, after-hours setting—by recognizing Slavitt’s role as “a key member of the team brought on to turn around HealthCare.gov during the first open enrollment period,” according to The Hill and other outlets.

Meanwhile, outside the Beltway, groups cheering the nomination included the Blue Cross Blue Shield Association and the pro-Obamacare consumer group Families USA, according to Reuters.

Throwing business-sector backing behind the move was Richard Anderson, CEO of Delta Air Lines. “As a former colleague I have witnessed firsthand how [Slavitt’s] thoughtful and devoted leadership translates to strengthening the health care services and programs that are crucial to millions of Americans,” Anderson said in published remarks. “I urge the Senate to take the next step to confirm Andy to this position.”

The confirmation hearings have yet to be scheduled.