Robert F. Kennedy Jr. returned to Capitol Hill Tuesday to try to make his case to Republican senators that he can lead the Department of Health and Human Services.

Also meeting with senators on Tuesday was Tulsi Gabbard, President-elect Donald Trump’s pick for director of national intelligence. She planned to meet with two Democratic senators on the Intelligence Committee and five Republicans.

Kennedy, who has come under fire for his opposition to vaccines and push to regulate farm-grown food, did not immediately discuss the topics he planned to bring up in his meetings, but several senators did share what their priorities are for the potential head of the HHS.

And some indicated they were ready to push back on Kennedy’s stances.

Sen. Josh Hawley, R-Mo., told reporters outside a Senate Judiciary Committee hearing that he did not agree with Kennedy on his agriculture positions and avoided commenting on his stance on abortion, but expressed optimism that Kennedy would “support President Trump’s policies” on all fronts.

“So my working assumption is he will stay in his lane and do HHS policy,” Hawley said, adding that he supports the polio vaccine.

Kennedy’s opinion on the polio vaccine has come under scrutiny after reports that his personal attorney Aaron Siri lobbied the Food and Drug Administration to revoke its approval of the vaccine. Sources told ABC News that Siri has been helping interview candidates for top health jobs in the incoming Trump administration. Siri, a partner at the law firm Siri & Glimstad, has also filed petitions seeking to pause the distribution of other vaccines, including Hepatitis B, and to revoke the emergency-use authorization of COVID-19 vaccines.

Sen. John Kennedy, R-La., was strong in his criticism of Siri.

Sen. Kennedy, who said he was “looking forward to sitting down” with RFK Jr. with an “open mind,” on Tuesday suggested to reporters outside a Senate Judiciary Committee hearing that the possible HHS secretary should fire his lawyer.

“I’ve got a completely open mind, but, but that kind of nonsense is not helpful,” Kennedy said of the polio misinformation.

“I hope to be able to get to a position where I can support him enthusiastically. I’m looking forward to his confirmation hearings. We take those seriously,” the senator added.

Sen. Tommy Tuberville, R-Ala., however, told reporters that Kennedy is a “breath of fresh air” who has his support.

Tuberville, who has no medical background, brushed off concerns about Kennedy’s views on vaccines and claimed, without any evidence or details, that they were not “100% proven.”

“He wants the parents to understand the good, the bad, and the ugly instead of just forcing parents to give vaccines to their kids,” the senator said.

Trump told reporters Monday that he was big believer in polio vaccine and vowed that it it was here to stay. He did, however, say he questioned vaccine mandates.

Kennedy told reporters Monday that “he was all for the polio vaccine.”

Sen. Thom Tillis, R-N.C., said he’d be meeting with Kennedy this week and looked forward to having discussions with him about vaccines and the agriculture industry.

Abortion, Tillis said, was a “legitimate question” he was going to ask Kennedy about.

“I am consistently and unapologetically pro-life since I was a member of the state legislature,” Tillis said.

One Senate Democrat, Dick Durbin of Illinois, told reporters he has not had any meetings with Trump’s potential nominees yet but that they should be vetted on abortion and vaccines, topics he called “life and death issues.” Durbin did not specifically mention Kennedy in his remarks.

“I think, in all fairness, we should take the measure of these nominees based on investigation, thorough FBI investigation, and what they have to say on the record under oath, and then make final judgment,” he said.

Gabbard on Tuesday said she had a “great” meeting with Democratic Sen. John Fetterman of Pennsylvania.

“This has been a great opportunity to meet with both Democrat and Republican senators and address any questions or concerns that they have and talk about the role,” she said.

Asked if she felt confident she had the votes to be confirmed, Gabbard said only that she “looks forward to meeting with senators as we continue through this process.”

Fetterman has been leading the charge among Democrats meeting with Trump’s nominees. In a post on X on Tuesday, he confirmed that he has met with Rep. Elise Stefanik, Trump’s selection for United Nations ambassador, and Pete Hegseth, his secretary of defense pick.

“I believe that it’s appropriate and the responsibility of a U.S. Senator to have a conversation with President-Elect Trump’s nominees,” Fetterman posted on on X. “My votes will come from an open-mind and an informed opinion after having a conversation with them. That’s not controversial, it’s my job.”

Gabbard was also expected to meet with Democratic Sen. Jon Ossoff and Republican senators Susan Collins, Dan Sullivan, Chuck Grassley, Lisa Murkowski and Rand Paul.

-ABC News’ Allison Pecorin and Beatrice Peterson contributed to this report.