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Sen. Marco Rubio: Trump is 'putting America first'

The senior U.S. senator from Florida spoke on the second day of the Republican National Convention in Milwaukee.

In a message of party unity, Florida Sen. Marco Rubio called on Republicans to fight "with our voices and our votes."

"Our country has been injured by bad decisions and weak leaders," he said. "But now, though bloodied by our wounds, we must stand up and we must fight. Fight not with violence or destruction, but with our voices and our votes."

Rubio tried to counter against more extremist portrayals of the party, saying what Trump supporters want is "not extreme," but things like lower prices, secure borders and security.

"And they want for our leaders to care more about our problems here at home than about the problems of other countries far away. There is absolutely nothing dangerous, or anything divisive about putting Americans first," he said, as the crowd broke out into a chant of "USA! USA! USA!"

Dr. Ben Carson, Trump's Housing and Urban Development secretary and former 2016 presidential rival, took the stage and argued that last week's assassination attempt was part of a long line of attacks against the former president.

"First, they tried to ruin his reputation, and he's more popular now than ever. And then they tried to bankrupt him, and he's got more money now than he had before. And then they tried to put him in prison, and he's freer and has made other people free with him. And then -- and then, last weekend they tried to kill him. And there he is over there, alive and well," Carson said to applause.

Carson did not specify who "they" were.

He went on to criticize the media and the government for dividing the nation contending the latter was "shredding our constitution and upending the rule of law.

During Florida Sen. Marco Rubio's remarks, the crowd chanted in honor of Corey Comperatore, the man killed during the assassination attempt on Trump during Saturday's rally.

"He was described as the best dad a girl could ever ask for," Rubio said. "He was a man of God who loved Jesus fiercely. He looked after members of his church. Corey was one of the millions of everyday Americans who make our country great."

Rubio continued, "He wasn't rich. He wasn't famous. And the only reason why we know his name and story now is because last Saturday, he shielded his wife and daughter from an assassin's bullet and lost his life the way he lived it, a hero."

The crowd then broke out into a chant of "Corey, Corey, Corey!"

Over and over again, the speakers on Tuesday night are taking jabs at Vice President Kamala Harris, going after her on immigration and arguing that a vote for President Joe Biden is a vote for Harris.

To be clear, Harris was tasked with addressing the root causes of immigration, not securing the border, but the spotlight on Harris is notable, especially given all the questions and concerns about Biden’s age.

But the argument that Harris is a drag on the ticket may be losing steam -- we have seen in recent days several polls showing Harris doing slightly better than Biden in a head-to-head matchup with Trump.

Of course, even Biden said Tuesday bluntly that Harris could be president, and he has argued a good one at that.

-ABC News' Mary Bruce