WASHINGTON — When Donald Trump steps up to the podium on the west terrace of the U.S. Capitol as the newly sworn-in president of the United States on Friday, he will deliver one of the most anticipated inaugural addresses in recent history.

“Everything about Donald Trump’s rise to the presidency has been so unexpected and so at odds with the traditional rules of modern presidential politics that it’s very difficult to predict what he’ll say in his address,” said Meena Bose, a presidential scholar at Hofstra University.

Trump won the presidency with blunt talk, showmanship and a feel for how to win the support of what he called “the forgotten men and women.” He has done little to change his voice during his transition, attacking critics and roiling foreign and domestic policy.

As a result, Trump has the lowest approval rating in history for a new president.

But Friday Trump can start anew with what is expected to be a short address that will give a glimpse of how he will carry himself as President Donald J. Trump.

“Expectations are so low that I really think he might be able to surprise people,” said Martin J. Medhurst, a rhetoric and political science professor at Baylor University in Waco, Texas.

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Great inaugural addresses are rare, and it is hard to do one well, Medhurst said.

Still, every new president aims to use the occasion to describe an agenda for action, offer a vision for the direction of the country and set the tone for his administration.

Here are five key things to watch for:

Reach out to his opponents

Trump has a core of loyal supporters who brought him victory in the Electoral College. But now Trump must reach out to the nation’s voters who gave Democrat Hillary Clinton a majority of the popular vote.

“Traditionally, the inaugural address has been a message of unity. We see that continuity in the fact that Hillary Rodham Clinton will be there when Donald Trump takes the oath of office,” said Bose.

Trump must say what he said on election night, “that he is president of all the people,” said Clark Judge, a special assistant and speechwriter to President Ronald Reagan.

Yet Trump’s biggest test may be the large numbers of protesters expected at the ceremony, said H.W. Brands, a University of Texas history professor. “He needs to make the protesters feel he is their president,” Brands said, “and not just the president of his supporters.”

Reassure the world

Like every new president, Trump needs to reaffirm the standing of the United States in the world and with its allies in Europe, Asia, Africa and Latin America.

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Yet Trump has stirred uncertainty about his foreign policy with praise for Vladimir Putin despite Russian attempts to interfere in the U.S. election, with criticism of NATO and European allies, and with a challenge to the one-China policy.

“In most inaugural addresses there is a brief section that is addressed to our allies and foes,” Medhurst said, and Trump must make clear “who are our allies and who are our foes.”

Define his presidency

During his campaign Trump made his top line priority clear: Make America Great Again.

Judge said he expects Trump to hit hardest on his campaign themes: control of the border, elimination of regulations that strangle the economy, restoring U.S. tax competitiveness, making America a place people want to invest in again, restoring security and repealing Obamacare.

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“The expectation is that the president takes the lead in agenda setting, in political leadership, in civil discourse,” Bose said.

“This is a turning point in American politics,” Bose said. “I think his approach will be: ‘Let’s get started.’”

Offer a vision of America

One goal of an inaugural address is to inspire the American people, to send them home feeling good about their new president.

“The inaugural address needs an element of uplift, and it’s hard to do,” said John J. Pitney, a politics professor at Claremont McKenna College in Claremont, Calif.

Also, Medhurst said that while Trump is not likely to be remembered for soaring rhetoric, he needs to do something he did not do at the Republican National Convention in Cleveland: “He must find a place to mention God.”

Find his voice as president

As campaigner and president-elect, Trump set the storyline each day with his tweets. But his words now take on greater weight.

“Now he’s speaking as president of the United States, so what he says as president matters a whole lot more,” said Brands.

“Trump has been playing the reality TV show host and acting as if he needs to do something outrageous to focus the cameras and microphones on him,” he said.

“Theodore Roosevelt, when he was out of office, he would do things to draw attention,” Brands said. “But when you are president you don’t need to shout. When you are in office, you are the story.”