Exxon Mobil CEO Rex Tillerson is President-elect Donald Trump's pick for secretary of state. (Eric Piermont/AFP)

Now that Donald Trump has named ExxonMobil CEO Rex Tillerson as his pick for secretary of state, the transition has reached a milestone of sorts. Nominations for the most prized jobs in the Cabinet -- the people who lead the Departments of State, Defense, Justice and the Treasury -- are all in place, filling what have come to be known as the "big four" jobs. As The Post wrote in 2011, these are the "original departments created by George Washington, with the heftiest portfolios" -- the most high-profile positions and among the foremost voices guiding the president's thinking on critical military, foreign affairs, justice and economic issues.

And for the first time in more than two decades -- if those four names are ultimately confirmed -- the "big four" jobs will be entirely white and male.

As one ABC News producer put it Tuesday:

One has to go back to George H.W. Bush's tenure to find a Cabinet where those jobs were all held by white men. Ever since Janet Reno was confirmed as President Bill Clinton's attorney general on March 11, 1993, a woman or a minority has always been in one of these top influential cabinet positions.

Reno, who died the day before the election this year and was the first female attorney general, served for eight years, longer than many cabinet appointees. Her tenure overlapped with Madeleine Albright, who became the first female secretary of state. Colin Powell, Condoleezza Rice and Hillary Clinton followed in that post. Alberto Gonzales, Eric Holder and Loretta Lynch have all held the Attorney General's job.

The secretary of defense and secretary of the treasury positions, meanwhile, have always been white men. Trump "will not be continuing the limited progress that had been made to make the inner cabinet look like America," said Anne Joseph O'Connell, a law professor at the University of California, Berkeley, in an email. O'Connell maintains a database of key government appointees going back to the Carter administration. "While this may be discouraging to many, it is not surprising."

Trump was known for blasting political correctness on the campaign trail. In November, Trump spokesman Jason Miller told reporters on a conference call that the executive branch "will be very broad and diverse, both with the Cabinet and the administration." An e-mail to a Trump spokeswoman was not immediately returned.

The people in these four big jobs typically have the highest profiles, said Douglas Brinkley, a presidential historian at Rice University. "Those are the original four posts," he said. "They’re the most powerful jobs in Washington. ... They're usually the most well-known. They're the slots that generate the most media. [They] get written about in the history books." Once they leave office, he says, publishers "want the memoir of the secretary of state. They don't want the memoir of the secretary of transportation."

They're also among the most influential voices guiding the president on the most far-reaching issues. "Who is advising and who is in that room when the door is closed?" said Debbie Walsh, director of the Center for American Women and Politics at Rutgers University. "We know there is value in having different perspectives in that mix. To not have the perspective of women or people of color in those key positions -- every indication is there is a cost to that."

In an e-mail, O'Connell said that "you have to look at more positions -- both at the very top and lower levels -- to get a meaningful sense of commitment to diversity in political agency appointments," and that so far, Trump's cabinet is less diverse in terms of gender, race and ethnicity than either President Obama's or President George W. Bush's first cabinets.

Many have noted this by now. For instance, Bloomberg on Thursday wrote that Trump is "building a cabinet in his own image," appointing a group of people with a combined net worth of some $5.6 billion. Some on the left have mocked Trump's cabinet diversity as "mixing billionaires with just plain multi-millionaires;" in recent days, a tweet from a former Hillary Clinton spokesman and commentary from MSNBC host Rachel Maddow about the lack of diversity at the top of the line of succession to the presidency have been shared widely on social media.

Trump has named women and minorities to his prospective Cabinet, but they have been picked for less central jobs. Billionaire heiress Betsy DeVos was nominated as secretary of education, and Elaine Chao is Trump's pick for transportation secretary. Ben Carson, who is black, is Trump's nominee for the Department of Housing and Urban Development.

South Carolina Gov. Nikki Haley, the daughter of immigrants from India, was selected as the ambassador to the United Nations, while the co-founder of the professional wrestling franchise WWE, Linda McMahon, is Trump's pick to lead the Small Business Administration. His campaign manager, Kellyanne Conway, the first woman to manage a winning presidential campaign, has said she could work as an outside adviser or potentially, as she said in a "Morning Joe" television appearance Thursday, on the inside.

Meanwhile, it's still possible Trump could still name more women or minorities to Cabinet or Cabinet-rank posts, though most of the names that have been floated for the remaining jobs have been white men. Trump still needs to name a secretary of agriculture and Veterans' Affairs secretary, as well as the director of the Office of Management and Budget, the U.S. Trade Representative, and the chairman of the Council of Economic Advisers. Reports Thursday said Trump was considering conservative pundit Larry Kudlow for that post.

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