Meghan McCain, the daughter of the late Sen. John McCain (R-Ariz.), said she will not support Vice President Harris or former President Trump in November.
Her comment came just hours after her brother, Jimmy McCain, threw his support behind Harris.
"I greatly respect the wide variety of political opinions of all of my family members and love them all very much," Meghan McCain wrote Tuesday on the social platform X. "I, however, remain a proud member of the Republican Party and hope for brighter days ahead. (Not voting for Harris or Trump, hope that clears things up)."
She did not touch upon who else, if anyone, she might support for the White House.
Responding to calls last month to endorse Harris's ticket, McCain said, "Please stop trying to turn me into a progressive."
"It's a fever dream," she added "I'm a life long, generational conservative."
McCain, 39, has frequently criticized Trump, who attacked her father numerous times when he was still alive.
In 2015, Trump came under harsh scrutiny for saying John McCain was not a war hero because he was captured. The senator, who died in 2018, was a prisoner of war in Vietnam for more than five years.
Jimmy McCain told CNN on Tuesday he changed his voter registration from independent to Democrat weeks ago and plans to vote for the vice president in the fall. He said he "would get involved in any way I could" to help Harris get elected.
Jimmy McCain, 36, served for 17 years in the military and is an intelligence officer. He also weighed in on Trump's recent visit to Arlington National Cemetery, calling the former president's conduct a "violation."
“It just blows me away,” he told CNN, referring to the reported incident. “These men and women that are laying in the ground there have no choice” about being in a political ad.
“I just think that for anyone who’s done a lot of time in their uniform, they just understand that inherently — that it’s not about you there. It’s about these people who gave the ultimate sacrifice in the name of their country,” Jimmy McCain added.
Trump visited the cemetery last week to mark the third anniversary of the U.S. withdrawal from Afghanistan. He was joined by some family of the 13 U.S. service members killed in the 2021 Kabul airport attack.
The former president said the family asked him to visit and to take pictures in the wake of criticism he was using the graves as a campaign backdrop.
A confrontation also reportedly took place when cemetery staff members tried to stop Trump’s campaign team from photographing and filming a solemn area of the cemetery dedicated to those who fought in the Iraq and Afghanistan wars.
Federal law prohibits political campaign or election-related activists within the cemetery, and the Army last week said an employee was pushed aside by the Trump team when trying to enforce the rules prohibiting political activities on cemetery grounds.
The GOP nominee and his team have pushed back on the claims, calling it a "made up story."