Cleveland (CNN) Melania Trump stepped onto center stage Monday for the highest-profile speech of her life, but the moment was quickly overshadowed by controversy after it emerged that portions of the speech were plagiarized from Michelle Obama's 2008 address to the Democratic National Convention.

Melania Trump initially appeared to deliver the speech her husband needed to portray him in a softer light. She offered testimony about the character of her husband, Donald Trump, and said he would never let America down.

The former fashion model, who rarely takes a leading role on the campaign trail, was the star attraction on the first night of the Republican National Convention.

"With all of my heart, I know that he will make a great and lasting difference," she said. "He will never give up and he will never, never let you down."

She went on: "Donald is and always has been an amazing leader. Now he will go to work for you."

Melania, 46, portrayed her husband as tough but kind and loyal. In an apparent attempt to soften his image following his calls for a temporary ban on Muslim immigration and his tough rhetoric on undocumented migrants, Melania said he would be a president for everyone, including Jews, Christians and Hispanics.

She was affectionate and spoke touchingly about how she fell in love with Trump. And she ruefully warned that the run-up to November's election could bumpy.

"The race will be hard, tough fought all the way to November," she said. "There will be good times and hard times and unexpected turns. It would not be a Trump contest without excitement and drama."

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Her speech capped a day of tumult as GOP officials crushed an attempt to change party rules, a maneuver that could have embarrassed Donald Trump . In addition to her speech, former New York Mayor Rudy Giuliani gave an especially impassioned address that brought many Republicans in the arena to their feet.

Melania Trump's address was warmly received by the rowdy Republican crowd, but did not include behind-the-scenes glimpses of life in Trump Tower or other details that might offer some insight into the man behind the image.

In an unusual move for a nominee, Trump appeared on a stage bathed in smoky light to introduce his wife to the sound of Queen's rock anthem, "We are the Champions."

"We are going to win, we are going to win so big. Thank you very much," Trump said in an uncharacteristically brief appearance of only one minute six seconds in the spotlight. He returned to the stage after Melania's speech -- beaming at his wife, as she planted a kiss on his cheek while he offered a thumbs up to the audience.

Melania has been working with a speechwriter for the last five to six weeks, honing her speech. She stuck close to script delivering her remarks off a telepompter.

Trump campaign manager Paul Manafort said that while Melania doesn't love the campaign trail, she was eager to deliver this speech.

When Trump's campaign first asked her if she wanted to do it, they thought she'd say no, according to campaign chairman Paul Manafort. But she quickly agreed and indicated she wants to be involved in showing the personal side of Trump and helping voters get to know her husband better.

There was be an emphasis on the personal, a window into the personality of the presumptive Republican nominee.

Melania Trump has been visible from the beginning of the Trump campaign, riding down the escalator of Trump Tower in a pristine white dress ahead of her husband's announcement.

But she is often seen more than she is heard. She is something of a reluctant campaign spouse -- preferring to stand by her man, but only making rare, brief cameras at the podium herself.

Trump's eldest daughter, Ivanka, often steps into fill that role. When Trump declared his candidacy last June, it was Ivanka who introduced her father, not Melania.

Despite a few quick words at the microphone in the early states of Iowa, New Hampshire and South Carolina, Melania's only real speech this election didn't come until April in Milwaukee on the eve of the Wisconsin's primary. And that speech clocked in at a mere ninety seconds.

"He's a great leader. He's fair. As you may know by now, when you are talking, he will punch back 10 times harder," Melania Trump told the crowd.

And, in perhaps the most memorable moment of the short speech, Melania delivered a very specific message at a time when Trump was embroiled in controversy over his past treatment of women.

"No matter who you are, a man or a woman, he treats everyone equal," she said.

But as she demurs from the spotlight, she is taking a strong behind-the-scenes role. Her voice carries real weight with a candidate known for his tight inner circle in which his family members are treated as his closest advisers.

"She said, if you run, you'll win," Trump recalled in Council Bluffs Iowa in January. "And almost from the day we announced we've been in first place. So here's my best pollster."

She has been known to step in at key moments during the campaign to help diffuse a situation, calling her husband out at some of the most controversial moments during his campaign, telling him to tone down his rhetoric or act more presidential.

"I don't try to change him. He's an adult. He knows the consequences. And so I let him be who he is," Melania told CNN's Anderson Cooper in a February interview . "I give him my opinions many, many times."

Trump has called her his "secret weapon" and praised her at campaign rallies for being "beautiful on the inside" and "smart."

A Trump campaign adviser said that while Melania hasn't been a force on the campaign trail, she watches a lot of the news coverage and is attuned to the political mood -- and she conveys those impressions to Trump.

But she's not a political spouse who's constantly weighing in.

"She knows her husband," the adviser said. "She doesn't inject herself unless she thinks it's necessary."