By Carol E. Lee 

WASHINGTON -- Donald Trump took office as the 45th president on Friday with a fiery address that echoed his campaign rhetoric, damning Washington's political order, and promising a new nationalism to shake up America's economy and international relations.

In a day draped in the pageantry and rituals that mark the transfer of power from one commander in chief to another, hundreds of thousands of Americans from across the country gathered in Washington under rainy skies both to celebrate and to protest.

Mr. Trump's inaugural address spoke squarely to his supporters. He took aim at the Washington establishment, sounded the nationalist themes that propelled his insurgent candidacy to the White House and painted a picture of a nation in distress.

"Every decision on trade, on taxes, on immigration, on foreign affairs will be made to benefit American workers and American families," he said. "Protection will lead to great prosperity and strength."

The combative tone of Mr. Trump's remarks played well to his supporters in the crowd, yet their dark nature surprised some historians and political strategists. "At some level, you expect an inaugural address to feature lofty, inspiring, and soaring rhetoric," said Lanhee Chen, who oversaw speech-writing for 2012 Republican presidential nominee Mitt Romney. "This was, instead, a statement of the harsh realities that helped propel Trump to the presidency."

The moment starts the clock on the ambitious agenda on which Mr. Trump has vowed to deliver, including new jobs, a sweeping health-care law to replace the Affordable Care Act, new immigration policies and major upgrades to America's infrastructure.

Despite the challenges he faces in achieving those goals, he set the country's expectations high. "I will never, ever let you down," he said.

In his 16-minute address, the new president lamented the "American carnage" of struggling families across a country he said is dotted with shuttered factories and decayed infrastructure and riddled with crime.

"For too long, a small group in our nation's capital has reaped the rewards of government, while the people have borne the costs," he said. "That all changes, starting right here and right now."

The president vowed to protect the U.S. from "the ravages of other countries."

"We defended other nations' borders while refusing to defend our own," Mr. Trump said. Going forward, he said, "we will follow two simple rules: buy American, and hire American."

Mr. Trump's bleak image echoed his campaign themes and ran counter to messages President Barack Obama delivered in his final appearances before leaving office on Friday.

Jobs lost to foreign competition in recent years have been replaced by jobs elsewhere in the economy, though they may pay less. Total employment is up by 11% since the end of the recession in 2009, or 14 million jobs.

Factory employment is up a much smaller amount -- 5%, or 549,000 jobs -- and is still lower than in 2007. That is probably partly due to trade, but mostly to rising productivity: the same output can be produced with fewer workers. U.S. manufacturing production has risen 21% since the end of the recession, and is slightly lower than in 2007.

Nationally, the murder rate rose in 2015 for the first time in nearly a decade, though it remains well below where it stood during the 1990s, according to the Federal Bureau of Investigation.

Mr. Trump also emphasized that he will be a different kind of commander in chief by using just three words -- he promised to unite the world against "radical Islamic terrorism." Mr. Obama refused for eight years to rhetorically mix Islam and terrorism. He argued doing so taints a religion that terrorists seek to exploit.

"We will reinforce old alliances and form new ones, and unite the civilized world against radical Islamic terrorism, which we will eradicate from the face of the Earth," Mr. Trump said.

At a luncheon in the Capitol's ornate Statuary Hall, Mr. Trump struck a softer tone.

"Whether you're a Republican or Democrat, doesn't make a difference, we're going to get along," he told a bipartisan crowd of lawmakers and dignitaries, including his 2016 election opponent, Hillary Clinton. Mr. Trump acknowledged Mrs. Clinton at the lunch, and shook her hand.

Underscoring the bitter election fight that preceded Friday's inauguration, as Mr. Trump prepared to make the customary presidential trip down Pennsylvania Avenue from the Capitol to the White House, protestors and police repeatedly clashed nearby.

Police arrested dozens of protestors and used tear gas to try to contain the situation, as thousands of Mr. Trump's supporters awaited the first family and the inaugural parade. Mr. Trump, his wife, Melania, his children and grandchildren watched the marching bands from viewing stands in front of the White House.

Mr. Trump had promised to make a number of major policy changes on the first day of his presidency but his aides said he'd defer most of them to Monday. He takes office with just two cabinet members in place, Defense Secretary James Mattis and Homeland Security Secretary John Kelly.

He has outlined an ambitious agenda for his first 100 days in office. Already he's encountering challenges, with Republicans disagreeing over the timing of a plan to repeal and replace Obamacare. Mr. Trump also will need some Democrats to help pass a replacement law, and Mr. Obama has urged members of his party not to help the GOP.

Mr. Trump's proposal to impose term limits on members of Congress hit a roadblock. Senate Majority Leader Mitch McConnell (R., Ky.) said the idea will not come up for a vote in his chamber.

He has also differed with congressional Republicans over the U.S. intelligence assessment that Russia used cyberattacks to try to interfere in the election in favor of Mr. Trump. Lawmakers have promised investigations into the matter and called for harsher punishment than the sanctions and diplomatic censures imposed on Russia by Mr. Obama. Mr. Trump, meanwhile, has expressed a willingness to consider lifting those sanctions if Russia takes steps on nuclear nonproliferation.

His signature promise, however, has been new jobs for the middle class. "The forgotten men and women of our country will be forgotten no longer, " he said in his address.

His speech was for some Democrats a poor start to any attempt to work with them.

"President Trump had an opportunity today to unite this country in his inaugural remarks," House Democratic Whip Steny Hoyer said in a statement.

"He chose not to do that, instead repeating the divisive rhetoric of his campaign and painting a dark picture of an America in decline -- something very far from the truth."

A New York businessman, Mr. Trump had never held elected office before Friday.

He took the oath of office with his hand on two bibles held by his wife, Melania.

Messrs. Obama and Trump participated in several inauguration rituals together. The outgoing and incoming presidents rode to the Capitol together in the presidential limousine, and the two couples posed together. The new president and first lady saw the Obamas off as they boarded a Marine helicopter on the back steps of the Capitol.

Write to Carol E. Lee at carol.lee@wsj.com

(END) Dow Jones Newswires

January 20, 2017 19:22 ET (00:22 GMT)

Copyright (c) 2017 Dow Jones & Company, Inc.