Certain Republican senators want public commitments from Robert F. Kennedy Jr. before deciding whether to support him as the next secretary of the Department of Health and Human Services, indicating that President Donald Trump’s pick will have to win over uncertain Republicans to secure the job. Iowa Republican Sen. Joni Ernst, an opponent of abortion rights, told CNN that Kennedy needs to do more to assuage her concerns given his past comments supporting access to the procedure. In addition, Republican senators and anti-abortion advocates have already raised concerns about Kennedy’s stance on abortion, his failed Democratic bid for president, and his past support for abortion access until fetal viability, which has been seen as a key vulnerability. This is not the only issue that Republican senators will press Kennedy on during a pair of high-profile confirmation hearings this week. Alaska Republican Sen. Lisa Murkowski, who was one of three Republicans to vote against Trump’s Department of Defense nominee last week, expressed concerns about Kennedy’s long history of sowing doubts about the safety and efficacy of vaccines. Kennedy has tried to allay concerns about his history of vaccine skepticism, including whether he supports the polio vaccine. However, Republican senators seem to remain cautious.