CASPER, Wyo. — Representative Liz Cheney was holed up in a secure undisclosed location of the Dick Cheney Federal Building, recounting how she got an alarmed phone call from her father on Jan. 6.
Ms. Cheney, Republican of Wyoming, recalled that she had been preparing to speak on the House floor in support of certifying Joseph R. Biden Jr.’s election as president. Mr. Cheney, the former vice president and his daughter’s closest political adviser, consulted with her on most days, but this time was calling as a worried parent.
He had seen President Donald J. Trump on television at a rally that morning vow to get rid of “the Liz Cheneys of the world.” Her floor speech could inflame tensions, he told her, and he feared for her safety. Was she sure she wanted to go ahead?
“Absolutely,” she told her father. “Nothing could be more important.”
Minutes later, Mr. Trump’s supporters breached the entrance, House members evacuated and the political future of Ms. Cheney, who never delivered her speech, was suddenly scrambled. Her promising rise in the House, which friends say the former vice president had been enthusiastically invested in and hoped might culminate in the speaker’s office, had been replaced with a very different mission.
“This is about being able to tell your kids that you stood up and did the right thing,” she said.
Ms. Cheney entered Congress in 2017, and her lineage always ensured her a conspicuous profile, although not in the way it has since blown up. Her campaign to defeat the “ongoing threat” and “fundamental toxicity of a president who lost” has landed one of the most conservative House members in the most un-Cheney-like position of resistance leader and Republican outcast. Ms. Cheney has vowed to be a counterforce, no matter how lonely that pursuit might be or where it might lead, including a possible primary challenge to Mr. Trump if he runs for president in 2024, a prospect she has not ruled out.
Beyond the daunting politics, Ms. Cheney’s predicament is also a father-daughter story, rife with dynastic echoes and ironies. An unapologetic Prince of Darkness figure throughout his career, Mr. Cheney was always attuned to doomsday scenarios and existential threats he saw posed by America’s enemies, whether from Russia during the Cold War, Saddam Hussein after the Sept. 11 attacks, or the general menace of tyrants and terrorists.
Ms. Cheney has come to view the current circumstances with Mr. Trump in the same apocalyptic terms. The difference is that today’s threat resides inside the party in which her family has been royalty for nearly half a century.