Jonathan Karl: What You Need to Know About the RNC Day 2

As the Republican National Convention gears up for day two, ABC News' Jonathan Karl breaks down the top three stories unfolding in Cleveland tonight.

Paul Ryan Takes the Stage

Speaker of the House Paul Ryan is slated to speak tonight at the GOP convention and he's expected to focus on the House Republicans' agenda, rather than solely praise Donald Trump.

"This is his speech," Karl said. "How much is he actually going to talk about Trump?"

Two days after Trump won the Indiana Republican primary, forcing his fellow candidates Ted Cruz and John Kasich to drop out of the race, Ryan declared that he was "not ready" to endorse his party's presumptive presidential nominee.

"I'm just not ready to do that at this point. I'm not there right now," the Wisconsin Republican told CNN's "The Lead with Jake Tapper."

Ryan finally endorsed Trump nearly a month later in June.

"I feel confident he would help us turn the ideas in this agenda into laws to help improve people's lives. That's why I'll be voting for him this fall," Ryan wrote in an op-ed for the Janesville Gazette. "It's no secret that he and I have our differences. I won't pretend otherwise. And when I feel the need to, I'll continue to speak my mind. But the reality is, on the issues that make up our agenda, we have more common ground than disagreement."

But Ryan hasn't hesitated to criticize Trump since then. He called the brash billionaire's remarks about a Latino judge "racist."

Protests against Trump's Nomination

Tonight, as part of the second day of the Republican National Convention, Trump's name will formally be put forward for the Republican presidential nomination and a roll call vote will take place. Although the outcome is inevitable, there's still an opportunity for anti-Trump protests and chaos inside the Quicken Loans Arena as the delegations vote state by state.

"They obviously cannot stop him, but they will try to do some theater to show that they're not satisfied," Karl said.

Trump Family Speeches

Melania Trump kicked off the parade of Trump family speeches with her first night address at the Republican National Convention. Tonight, Donald Trump's 22-year-old daughter from his second marriage will take the stage for her first speech on the campaign trail.

Unlike her older siblings, Tiffany Trump rarely gives interviews and has largely shied away from the spotlight surrounding her father's presidential campaign. She's appeared at only a couple of campaign events where her siblings were also in attendance.

Trump's eldest son, Donald Trump Jr., will also deliver remarks tonight.

The Trump kids' speeches come as Melania Trump, the real estate mogul's third wife, is accused of plagiarizing Michelle Obama's address to the Democratic National Convention eight years ago.

"I imagine we'll have no plagiarism issues or any related issues. They're probably combing over those speeches very carefully tonight," Karl said.

Donald Trump's campaign chairman, Paul Manafort, flatly denied allegations that Melania Trump lifted her speech last night from Michelle Obama's in 2008.

"To say that she lifted any words from anybody is absurd," Manafort told ABC News' Tom Llamas. "Her speech last night was a very poignant presentation of her becoming an American citizen, falling in love with a man that she wanted to talk about."

ABC News' Meghan Keneally contributed to this report.