What is Kash Patel's 'enemies list' that's delayed his confirmation as FBI chief?

Democrats have delayed Indian-origin Republican Kash Patel's confirmation as FBI Director under President Donald Trump, claiming he intends to target Trump's opponents. They've cited an 'enemies list', published in Patel's 2022 book, which names over 60 individuals (politicians, journalists, government officials), some of whom prosecuted Trump. Patel said it's not a tool to target Trump's critics.