(WASHINGTON) — Calling President Donald Trump “unfocused and undisciplined,” a former chief of staff at the Department of Homeland Security has endorsed former Vice President Joe Biden’s bid for the presidency.

“Given what I’ve experienced in the administration, I have to support Joe Biden for president,” former Trump administration official Miles Taylor said in a video posted and produced by the group Republican Voters Against Trump. “And even though I’m not a Democrat, even though I disagree on key issues, I’m confident that Joe Biden will protect the country, and I’m confident he won’t make the same mistakes as this president.”

Taylor is a lifelong Republican who served as former DHS Secretary Kirstjen Nielsen’s chief of staff. He said what he saw working day-to-day in the Trump administration “terrified” him, and accuses Trump of repeatedly exploiting the department to serve his own political agenda.

He also detailed what the president said were “magical authorities” even when top aides would say a particular policy was illegal.

“[Trump] was one of the most unfocused and undisciplined senior executives I’ve ever encountered,” Taylor said in the video.

“He wasn’t interested in those things,” Taylor said of trying to talk to the president about issues such as a cyberattack or a terrorism threat. “The president wanted to exploit the Department of Homeland Security for his own political purposes and to fuel his own agenda.”

The new accusations about the president’s conduct also detail allegations that Trump tried to cut off funding to deal with wildfires in California because the state is run by Democrats.

“He told us to stop giving money to people whose houses had burned down from a wildfire because he was so rageful that people in the state of California didn’t support him, and that politically it wasn’t a base for him,” Taylor said in the video.

White House spokesman Judd Deere said in a statement that Taylor is “another creature of the DC swamp who never understood the importance of the President’s agenda or why the American people elected him and clearly just wants to cash-in.”

Taylor said he’s “confident Biden will protect the country” and not make the same mistakes Trump has.

Asked to respond to comments from a White House official questioning why Taylor continued to serve if he had such a problem with the Trump administration, Taylor told ABC News that’s exactly the reason.

“If I thought the president was incompetent, why did I continue to serve? For exactly that reason. Most people who joined the administration saw plainly that the president was ill-prepared for his job and would need people who knew what they were doing,” Taylor said in a statement. “We were foolish for hoping he would rise to the occasion (he didn’t), that he could be fixed (he couldn’t), and that his presidency wouldn’t be that bad (it was worse).”

In a subsequent op-ed in the Washington Post, Taylor says that the president once demanded a DHS briefing to determine the color of the border wall in February 2019 amid a potential second government shutdown.

“He was particularly interested in the merits of using spray paint and how the steel structure should be coated. Episodes like this occurred almost weekly,” Taylor wrote.

Senior White House adviser and presidential son-in-law Jared Kushner said Monday on CNN that Taylor “was a nice kid” who “wasn’t up to the task.”

“Look, Miles was a nice kid,” Kushner said. “He worked here for a couple of years. But I will say that it makes a lot of sense to me that he’s endorsing Joe Biden.”

John Cohen, a former acting under secretary at the Department of Homeland Security, told ABC News that Taylor “confirms what many of us who worked at DHS have observed from the outside.”

“Under this administration, the department created to safeguard the nation from foreign and domestic threats has been used by this White House as nothing more than a partisan political instrument,” Cohen, an ABC News contributor, said. “It also confirms why there have been so many operational breakdowns involving the department over the past 3.5 years.”

A source inside the Department of Homeland Security told ABC News that people in the department were surprised, baffled and angry to learn of Taylor’s comments.

Spokespeople for the Department of Homeland Security did not immediately respond to ABC News’ request for comment.

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