Former Vice President Dick Cheney and his daughter, former GOP Rep. Liz Cheney, at the opening of the 115th Congress on Capitol Hill in 2017. Donald Trump lashed out at the Cheneys after they announced they would vote for Democratic presidential nominee Kamala Harris. IM WATSON/AFP via Getty Images

Donald Trump blasted former Vice President Dick Cheney as "irrelevant" after the Republican said he would vote for Democratic presidential candidate Kamala Harris, emphasizing that the former president "can never be trusted with power again."

The announcement by the steadfast conservative Republican came a day after his daughter, former GOP Rep. Liz Cheney, who was a co-chair of the congressional committee investigating Trump's role in the Capitol riot on Jan. 6, 2021, said she was also backing Harris.

"Dick Cheney is an irrelevant RINO, along with his daughter, who lost by the largest margin in the History of Congressional Races!" Trump lashed out at Cheneys on his Truth Social network.

Dick Cheney, 83, has a long history in the Republican Party, serving at different times as White House chief of staff, Defense secretary and vice president in the George W. Bush administration.

He released an alarming statement Friday warning about the consequences of electing Trump again.

"In our nation's 248-year history, there has never been an individual who is a greater threat to our republic than Donald Trump," he said. "He tried to steal the last election using lies and violence to keep himself in power after the voters had rejected him. He can never be trusted with power again."

As "citizens, we each have a duty to put country above partisanship to defend our Constitution. That is why I will be casting my vote for Vice President Kamala Harris," Cheney continued.

Trump seized on Cheney's role in the Iraq war and Liz Cheney's 2022 election loss in Wyoming to a Trump-backed candidate to needle the father and daughter.

"He's the King of Endless, Nonsensical Wars, wasting Lives and Trillions of Dollars, just like Comrade Kamala Harris. I am the Peace President, and only I will stop World War III!," Trump said.

"What Liz Cheney did with the Unselect Committee of Political Losers is unthinkable. She and her Unselects deleted and destroyed all evidence and information — IT'S GONE," the Republican presidential nominee said.

"Cheney and the others should be prosecuted for what they did, but Comrade Kamala is even worse!," he added.

Liz Cheney announced Thursday that she would vote for Trump's Democratic rival over him.

"As a conservative, as someone who believes in and cares about the Constitution, I have thought deeply about this. Because of the danger that Donald Trump poses, not only am I not voting for Donald Trump, but I will be voting for Kamala Harris," Liz Cheney said.

In his attacks on the Cheneys, Trump reached into the past to evoke the name of Scooter Libby, Dick Cheney's one time chief of staff who was convicted in 2007 for obstructing justice in the Valerie Plame case.

Trump pardoned him in 2018.

"They couldn't get Scooter Libby, who did so much for them (but was so unfairly treated!), PARDONED. I did it!," Trump said.