In 2021 Joe Biden was the oldest American ever to be sworn in as president, at age 78. From day one of his presidency there was speculation he would step down for a younger Democrat rather than seek reelection. After Democrats outperformed expectations in the midterms, however, Biden supporters gained momentum. In April 2023 Biden announced he would run for reelection as president. He won New Hampshire's Democratic primary despite his name not appearing on the ballot after supporters organized a write-in campaign.

Dean Phillips announced he was challenging president Biden for the Democratic nomination in October 2023. He said, "I think President Biden has done a spectacular job for our country. But it's not about the past. This is an election about the future. I will not sit still I will not be quiet in the face of numbers that are so clearly saying that we're going to be facing an emergency next November." Phillips has served three terms in the U.S. House of Representatives and is one of the wealthiest members of Congress, thanks to his successful business ventures. He lost to Biden in New Hampshire's Democratic primary.

Williamson has been described as a self-help author, spiritual advisor, and activist. She criticizes Biden and other Democratic Party leaders for policies that favor wealthy donors over working class voters – including efforts to bump New Hampshire later in the presidential primary calendar. She suspended her campaign in early February, then "un-suspended" her campaign after the Michigan primary on February 27. She acknowledged her slim chances at victory but said, "something so much more important than the horse race is at stake here. And we must respond."

Nikki Haley served as governor of South Carolina and U.S. ambassador to the United Nations under president Trump. Her campaign announcement in February 2023 included a clear jab at both Trump and Biden: “America is not past our prime, it’s just that our politicians are past theirs.” Haley dropped out of the race after Super Tuesday in March 2024 but has not endorsed Donald Trump.

Shortly after the 2022 midterm election former president Donald Trump announced his third presidential campaign from Florida. Sticking with his previous campaign catchphrase, he said, “Our country was great. Our country is not great anymore.” He is a formidable campaign fundraiser, but not all Republicans are as enchanted with him as they were in the past. Still, he has emerged as the frontrunner, handily winning the New Hampshire Republican primary.