For all the lingering tensions between President Donald Trump and former President George W. Bush, Trump’s White House shares one thing in common with his Republican predecessor’s: People.

Trump famously repudiated Bush's foreign policy during the 2016 South Carolina Republican Primary saying that Bush lied to start the war in Iraq, was responsible for not keeping the U.S. safe on 9/11 and vowed no more "stupid wars" the Middle East.

Trump at the time was running on an isolationist foreign policy that he has yet to act on, in fact Defense One reported Monday that Trump has increased U.S. troops in the Middle East almost 35 percent in the last four months from 40,517 to 54,180 - using data from the U.S. Department of Defense, which excludes Afghanistan.

Trump's troop increase perhaps should come as no surprise given he has installed more than three dozen veterans of the Bush administration, putting them in charge of running agencies, implementing foreign policy and overseeing his schedule. While hiring from the last administration controlled by the same party is common, Trump’s staffing moves are notable given his pledges to change politics-as-usual and the frosty relations between the current and former Republican standard-bearers.

The Bush influence has only grown stronger recently, as Trump nominated Alex Azar to lead the Health and Human Services Department, where he served under the Bush administration, and tapped Jerome “Jay” Powell to be chairman of the Federal Reserve. Powell served in the Treasury Department under President George H.W. Bush.

While the White House says this is standard practice, some Trump allies say the hires don’t fit with the president’s non-traditional style.

“If Donald Trump’s presidency fails it will be because he has perhaps inadvertently surrounded himself with” Bush associates, said longtime Trump associate Roger Stone.

The Bush alums in the administration include Transportation Secretary Elaine Chao, who served as Bush’s labor secretary, and Dina Powell, a deputy national security adviser who oversaw White House personnel and later served in Bush’s State Department under Condoleezza Rice. Even the president’s schedule and day-to-day operations are overseen by a former member of Bush’s inner circle: Joe Hagin, who served as deputy White House chief of staff.

Of course, hiring staffers from a past administration brings needed experience.

“These are complex jobs and the time is limited,” said Mike Leavitt, a former Utah governor and Health and Human Services secretary under Bush. He pointed to the importance of understanding the complexities of federal regulations, the budget and congressional relations. “If everyone has to learn it anew the chances of implementing an agenda are substantially reduced and the quality of government isn’t as good.”

Still, the commingling follows a campaign in which Trump repeatedly dismissed Bush’s handling of the Iraq war and his administration’s focus on nation-building overseas and branded his brother, former Florida Gov. Jeb Bush, as “low-energy Jeb” during the Republican primaries.

In a pointed speech last month, George W. Bush — without mentioning Trump by name — denounced bigotry coursing through present-day American politics, warning that “we’ve seen nationalism distorted into nativism,” and the “return of isolation sentiments, forgetting that American security is directly threatened by the chaos and despair of distant places.”

Trump vented his frustration about Bush’s speech to a former adviser, arguing that it represented another attack aimed at undermining his presidency, according to a person familiar with the conversation who spoke on condition of anonymity to describe the private conversation.

Traveling aboard Air Force One at the start of his recent trip to Asia, Trump was asked by reporters to respond to Mark K. Updegrove’s new book, “The Last Republicans,” in which the elder Bush calls Trump a “blowhard” and George W. Bush wonders if he would be the last Republican president.

“I’ll comment after we come back. I don’t need headlines. I don’t want to make their move successful,” Trump said. The president has yet to comment on the recent Bush criticism.

Of course, not all former Bush advisers are jumping into the current administration. Bush’s former top adviser Karl Rove, for example, has been a vocal critic of Trump, and many former Bush foreign policy advisers denounced Trump’s views during the campaign.

Trump allies, like Stone, question if the hires are shifting Trump’s policies away from his campaign pledges. He said there has been a softening of Trump’s isolationist policies, noting his missile strike in Syria and agreement to send more U.S. troops to Afghanistan. Stone also questioned the plans to limit tax deductions for state and local taxes as part of a proposed tax overhaul approved Thursday by the House.

“If you told me that a Republican president was going to get elected and his tax reform would have me paying more? That’s George Bush. He said read my lips, no more new taxes,” Stone said of the 41st president. “What genius came up with repealing state and local? That’s just a tone deaf idea.”

White House officials said it was only natural for Trump to cultivate former members of the Bush administration.

“I have to imagine there is going to be overlap since he was the last Republican president,” said Marc Short, the White House’s director of legislative affairs who worked in the Homeland Security Department during the Bush administration. Indeed, the list is long.

Trump’s labor secretary, Alex Acosta, was appointed by Bush to the National Labor Relations Board and later served in the Justice Department’s civil rights division and as a top federal prosecutor in South Florida. Dan Coats, a former Indiana senator and U.S. ambassador to Germany under Bush, is Trump’s director of national intelligence.

When the president grappled with a series of debilitating hurricanes in Texas, Florida and Puerto Rico this year, his most high-profile responders were from Bush’s network, including Tom Bossert, the administration’s homeland security adviser; Brock Long, the administrator of the Federal Emergency Management Agency; and Elaine Duke, who took over Homeland Security on an acting basis when Trump named John Kelly his chief of staff.

Trump’s nominee to head Homeland Security, Kirstjen Nielsen, worked for the agency during the Bush administration.

“Republicans who have White House experience or broader administration experience, they either got it under Bush 43, or they’re pretty old,” said Josh Bolten, White House chief of staff under Bush. “So it’s a natural place to look. It is the farm system.”