GRAND RAPIDS, Mich. (WOOD) — President-elect Donald Trump continues to build out his Cabinet. Not surprisingly, some of those choices are controversial and candidates may face an uphill battle to be confirmed.

Robert Kennedy, Jr., a longtime environmental lawyer and son of the former U.S. attorney general, will be nominated for the position of Health and Human Services secretary. His controversial position on vaccines may be a stumbling block, even for Republicans, who will have the majority in the Senate when Trump resumes office in January.

After Kennedy had jettisoned the Democratic party in which his family played such a storied role and before he threw his weight behind Trump, he himself had designs on becoming president with a longshot independent bid. Some of his campaign issues are now a key underpinning to his nomination.

When he was campaigning in West Michigan earlier this year, he told News 8 how he views the challenges in health care and why he says it’s a crisis.

“We have a chronic disease epidemic in this country that makes us the sickest country in the world: autoimmune disease, allergies, food allergies, eczema, asthma and neurological disease, ADD, ADHD, tics, autism and obesity. There’s no other country in the world that is as sick as us and nobody’s asking the question: Why are our kids the sickest in the world? Why do we have the highest death rate from COVID of any country on earth? We had 16% of the COVID-19 deaths, we only have 4.2% of the world’s population. If you ask CDC that question, what they’d say that’s because Americans have the highest burden of chronic disease in the world,” he said.

Kennedy may not have a smooth path to confirmation. But drawing potentially even more criticism is former U.S. Rep. Matt Gaetz of Florida, who Trump has picked for attorney general, and Fox News host Pete Hegseth for defense secretary.

Presidents typically get most of the people they choose, but, while rare, it is not unheard of for the Senate to reject some nominees, too. The last time was when Republican Sen. John Tower was voted down for secretary of defense in 1988. More common is presidents moving to withdraw nominees or nominees withdrawing their names from consideration — that has happened in each of the last six presidents’ tenures.