– Republican lawmakers said hearings on Sylvia Mathews Burwell’s nomination as U.S. Health and Human Services secretary provide a fresh opening to raise questions about President Obama’s health care law.

Obama’s choice of Burwell, the director of the Office of Management and Budget, to succeed Kathleen Sebelius will “elevate some of the concerns” that Republicans have about the law, Representative Marsha Blackburn of Tennessee said on CBS’ “Face the Nation” program.

She and other Republican lawmakers said they want details on how many enrollees have paid for their plans, the age composition of the enrollees and how that will influence insurers’ decisions to raise prices next year.

After initial stumbles, the program beat initial forecasts as the first open enrollment period ended March 31. About 7.5 million people signed up for private health insurance through the Patient Protection and Affordable Care, Sebelius told a Senate hearing Thursday, hours before her resignation was announced.

Lawmakers should use Burwell’s confirmation hearings to “figure out first and foremost who actually has benefited from the so-called success of Obamacare and its rollout,” Sen. Tim Scott, a South Carolina Republican who sits on the Health, Education, Labor and Pensions Committee, said on “Fox News Sunday.”

Republicans have said that the health care law will be a central theme of their campaign to defend their U.S. House majority and win control of the Democratic-held Senate in the November elections.

Democrats will use Burwell’s confirmation hearing to “tell the real human stories” about the health law’s benefits, said Sen. Sheldon Whitehouse, D-Rhode Island.

Burwell’s nomination is subject to confirmation by the Senate, where Democrats control 55 of the 100 seats. The Senate last year confirmed Burwell for the OMB post on a 96-0 vote.