President Donald Trump has informed various aides and allies that he is considering replacing Commerce Secretary Wilbur Ross after he failed to secure the addition of a citizenship question to the 2020 census, said several people familiar with the conversations.

While the president has previously expressed frustration with Ross’s performance as Commerce Secretary, the cabinet official has so far been spared from Trump’s ire due to the close personal relationship between the two. The resignation of Alex Acosta, the former Labor Secretary, may also have bought Ross more time, as the president may be reluctant to be relieved of two key department heads so close together.

Some White House officials still expect for Ross to be the next name on the long list of former Trump cabinet heads, saying that his possible exit could occur as soon as this summer.

Frustrated by Ross’ leadership of the Census Bureau, which is a part of the Commerce Department, the president has been making calls to other allies outside the White House in which he discussed removing Ross.

When asked about the president’s dissatisfaction with him, Ross, speaking at a Made in America showcase at the White House Monday, did not directly answer the question, instead opting to assert that “we’re here to celebrate.”

While it is not uncommon for the president to remove a cabinet member from office, if Ross vacated his post it would be the first time that one of Trump’s close personal friends would leave the White House.

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The two first met and bonded in the 1990s during the bankruptcies of Trump’s Atlantic City casinos, as Ross represented some of the future president’s creditors. The pair then continued their friendship for over 25 years, with both owning nearby residences in Manhattan and Palm Beach, Florida. Ross, a registered Democrat, endorsed Trump in 2016, saying, “We need a more radical, new approach to government.”