Ronald Kessler, a former Washington Post and Wall Street Journal investigative reporter, is the New York Times bestselling author of The First Family Detail: Secret Service Agents Reveal the Hidden Lives of the Presidents, The Secrets of the FBI and The Trump White House.

The ouster of Secret Service Director Randolph D. 'Tex" Alles on Monday was not unexpected, and, in fact, was welcomed by most members of the law enforcement agency, sources tell DailyMail.com.

'The sentiment at the agency is "good riddance,"' they say.

'Alles seemed more interested in making friends with agents than fixing the problems that plague the once-proud agency,' according to agency sources. 'He proved to be the exact opposite of what was needed to reform the agency. '

His idea for trimming costs was to get rid of protection for members of the Trump family.

Nothing changed within the Secret Service since the party-crashing Salahis went prancing into the White House State Dinner back in 2009, or since the Secret Service prostitution scandal in 2012 or since Omar Gonzalez was able to penetrate his way into the White House with a knife before being apprehended in 2014.

The change comes on the heels of an embarrassing episode at Trump's private Mar-a-Lago resort club in Palm Beach, Florida, involving a Chinese national on a club guest list who was arrested with devices bearing computer malware.

Secret Service punted responsibility to Mar-a-Lago's private security detail.

The appointment of Alles on April 25, 2017 was pushed on the president by General John F. Kelly, then Secretary of Homeland Security and later White House Chief of Staff.

Sources tell DailyMail.com that Kelly threatened to quit as DHS secretary if Trump did not appoint Kelly's friend Tex.

According to Steve Bannon, Trump had another nominee in mind: George Milligan, a sharp veteran agent who is chief operating officer of the Secret Service. But General Kelly wanted him [Alles} in the worst way, Bannon said.

Alles is pictured in the Oval Office with the president in April 2018; he fired Alles less than a day afte rdhowing Homeland Security Secretary Kirstjen Nielsen out the door

When he interviewed Alles, Trump was not impressed. Alles volunteered that he knew next to nothing about the Secret Service.

'Apparently it was too much trouble to read books and articles about the agency or to check out the Secret Service website before meeting with the president,' wrote Kessler in The Trump White House.

Agents were unimpressed with Alles and largely ignored him.

Alles not only retained the same senior management that produced so many scandals, he did nothing to change the agency's culture that has led to those scandals and the low morale that has resulted in a shockingly high turnover rate.

At one point Alles actually proposed saving money by withdrawing Secret Service protection of some Trump family members and some aides - unless they had actually received a threat.

Throughout history, none of the assassinations of assassination attempts have been preceded by a threat.

Horrified White House staff immediately shot down Alles' proposal to cut back on protection.

Especially given the hatred directed at Trump and his family, the idea of the director of the Secret Service would entertain dropping protection of the president's family members is inself a scandal and all anyone needs to know about why Alles should be replaced before a tragedy occurs.

Press Secretary Sarah Sanders said in a statement that Alles 'has done a great job at the agency over the last two years, and the President is thankful for his over 40 years of service to the country.'

'Mr. Alles will be leaving shortly and President Trump has selected James M. Murray, a career member of the USSS, to take over as director beginning in May.'

Shoving Alles overboard is an indication of the growing power of Trump adviser Stephen Miller, the 33-year-old former staffer to Sen. Jeff Sessions before he was the president's first attorney general.

President Donald Trump fired U.S. Secret Service Director Randolph Alles on Monday, signaling a plan to toughen the ranks of officials tasked with carrying out his hard-edged border policy

The twin killings of Nielsen adn Alles indicate the strong hand of 33-year-old Trump aide Stephen Miller, a former aide to then-Senator Jeff Sessions who has become the driving force behind the administration's immigration policy

A White House source with knowledge of the West Wing's goings on in the past week told DailyMail.com on Monday that Miller has advocated internally for Nielsen's firing, and for Alles to follow her out the door.

Miller is known as a sharp-tongued promoter of hawkish immigration policies that Democrats have complained push the boundaries of federal law and too often challenge court precedents.

Trump fired Nielsen in a tweet on Sunday shortly after meeting with her in the White House residence and hearing her plan for bringing U.S. immigration in line with legal limitations.

Secret Service agents arrested Yujing Zhang, a Chinese woman, last week when she tried to enter Mar-a-Lago with two Chinese passports, a thumb drive with malware on it, four cellphones, a laptop and a hard drive.

Trump said at the time that he was 'not concerned at all' about the potential breach by Zhang, who posed for a picture with him at his Super Bowl party this year.

'Secret Service is fantastic. These are fantastic people. And the end result is it was good,' Trump said last Wednesday.

'The result is they were able to get her and she's now suffering the consequences of whatever it is she had in mind but I would say I could not be happier with Secret Service. Secret Service has done a fantastic job from day one. Very happy with them.'

White House Deputy Press Secretary Hogan Gidley said earlier on Monday that with an influx of illegal immigrants pouring into the U.S. from the south, 'tt's time to do things a little differently.'

'And so the president is looking around to reshape his team so that he can have the people in place to carry out his agenda,' he said during a Fox News Channel interview. 'And quite frankly he has the right to do that.'

The Secret Service is best known for protecting the president and vice president and their families, and those who formerly served in office.

Established in 1865, the agency also investigates and prevents counterfeiting in order to protect the U.S. financial system, and combats computer-based financial crimes.

The Secret Service was originaly a subagency of the Treasury Department, when it was principally an anti-counterfeiting force.

It became a branch of the Homeland Security Department in 2003 as the new post-9/11 agency coalesced around a mission that unified a group of previously far-flung government agencies.