Sen. Marco Rubio (R-Fla.) listens to a prayer before speaking at a campaign rally at Palm Beach Atlantic University in West Palm Beach, Fla., on March 14, 2016. (AP/Paul Sancya)

WEST PALM BEACH -- Giving what sounded like a valedictory address, Sen. Marco Rubio on Monday cited "the disintegration of our culture" for the increasingly nasty nature of American politics.

Rubio made the comments amid a final campaign bus trip along the eastern coast of Florida before Tuesday's Republican presidential primary. The journey began early Monday in Jacksonville and was scheduled to conclude Monday night just blocks from his home in West Miami.

The senator spoke at Palm Beach Atlantic University, a predominantly Christian institution, in front of hundreds of students and local residents. He recalled the start of his presidential campaign 11 months ago at Miami's Freedom Tower, "The Ellis Island of Cuban-Americans." He spoke frequently about his late father and grandfather and his mother, the struggles they faced shortly after immigrating to the United States and how their hard work launched him on the course he's on today.

But speaking on an elevated stage in the middle of a gymnasium, Rubio frequently lamented the caustic nature of American politics -- spurred by GOP front-runner Donald Trump -- that he said is making the United States "a nation where people literally hate each other, because they’re voting for different candidates."

He faulted "the disintegration of our culture. We have a culture where what used to be considered wrong is considered right. My whole life I was told that being humble is a virtue. And now, being humble is a weakness and being vain and self-absorbed is somehow a virtue," he said. "My whole life I was told that no matter how you feel about someone, you respect them because we’re all children of the same God. And now, being respectful to one another is considered political correctness and therefore it goes too far."

"We have never had a presidential candidate that has to be bleeped out," he told the crowd, sounding despondent.

"Presidents can’t say whatever they want to say. You have to be honest, you have to be correct and you have to be truthful – but you cannot say whatever you want to say," he added.

"The presidency is not a reality TV show. It’s not the political version of 'Survivor,'" he said. "I know policy debates can get boring. I know that the ones where we call each other names are a lot more exciting. But we’re not a third-world country. We’re the United States of America – we’re the most important country on earth. And you deserve what its leader is going to do when elected president."

Rubio also apologized again for the more personal attacks he employed against Trump, including a focus on the businessman's personal appearance.

"It embarrassed my children. It embarrassed my wife. It embarrassed young people who followed my campaign. And I felt terrible about it," he said.

Rubio is scheduled to appear later Monday at a community center in West Miami -- just blocks from his home. He will rally with supporters on Tuesday night at Florida International University, where Rubio has been a part-time professor.

Amid a litany of concerns with the nation's health-care system, economic growth and standing in the world, Rubio -- always eager to convey optimism from the stump -- declared that "all these problems I just outlined, every single one of them can be fixed."

"We need you!" someone shouted in the crowd.

"I’m working on it," Rubio said.