Who Are The Republican Senators Who Could Block Some Of Trump's Most Controversial Appointments

President-elect Donald Trump has started the nomination process to fill his cabinet, most notably bringing forward some controversial names like Florida Rep. Matt Gaetz, former Democratic Rep. Tulsi Gabbard and Robert F. Kennedy Jr.

But before they start their respective roles, they need to be confirmed first by the Senate, which, although will be under Republican rule come January, will also contain a small but decisive group of potential GOP dissidents.

Having a Senate reject a nominee from the president is extremely rare. In fact, the only time a nominee by a new president was denied by a Senate vote occurred in 1989, when George H.W. Bush nominated John Tower, a former senator from Texas, to be his secretary of defense.

Tower's reputation followed him. His colleagues often told stories of his excessive drinking and the press reported his actions as "womanizing," with Pentagon files back then documenting him as placing "special attention on the secretaries" as an arms negotiator in Geneva.

Tower's story resembles that of Florida Rep. Matt Gaetz, the President-elect's pick to be attorney general. Gaetz has been the subject of a federal investigation for sex trafficking by the Department of Justice— the same agency he would lead if he is confirmed for that role. His nomination in particular has raised eyebrows among fellow GOP members. He was also investigated by the House Ethics Committee, which was set to vote on releasing its "highly damaging" content before Gaetz resigned right after being nominated.

"It must be the worst nomination for a Cabinet secretary in American history," said John Bolton, former U.N. ambassador and national security adviser. "I think this is something that falls well outside the scope of deference that should be given to a president in nominating members of the senior team. Gaetz is not only totally incompetent for this job. He doesn't have the character. He is a person of moral turpitude."

But while Republicans have a Senate majority, theoretically making it easier to breeze through nomination approvals, a small section of the party who has shown opposition to some of the nominees' names or Trump himself may prove decisive in shaping the incoming Cabinet.

Incoming Senate Majority Leader John Thune (R-S.D.) can afford to lose three Senate GOP votes on Trump nominees. But at least six Senate Republicans, depending on the specific nominee, could cast their vote to block Trump's decision, according to Axios.

One of the most prominent names in this list is outgoing GOP leader Sen. Mitch McConnell (R-Ky.), who will no longer be facing pressures of future leader elections and who has been a longtime critic of Trump, most recently backing special counsel Jack Smith, saying he hopes Trump will "pay a price" for his role in Jan. 6, according to a recently published biography.

Sens. Susan Collins (R-Maine) and Lisa Murkowski (R-Alaska) will also be critical GOP votes. They are two of the only three Republican senators left who voted to convict Trump in an impeachment trial. Neither have endorsed him this year, and they have been constantly critical of him. They have also voted in line with GOP colleagues only around 36% of the time this year.

Other names that could mess up Trump's Senate math include Sen. Thom Tillis (R-N.C.) who is up for reelection in 2026 and is likely to face a strong Democratic challenger without Trump on the ballot. Likewise, Sen. Todd Young (R-Ind.) refused to endorse Trump this cycle. Finally, the newly elected Sen. John Curtis from Utah is expected to at least partially follow in the shoes of retiring Sen. Mitt Romney (R-Utah) as a more moderate voice in the conference.

Ahead of Inauguration Day on Jan. 20, it remains to be seen whether this group will stick to the tradition of approving the president's appointments or whether they will show resistance.