Donald Trump is "insecure" and "touchy," says Sen. Marco Rubio (R-Fla.), according to CNN. Rubio was firing back at Trump after the real estate mogul paid him a few public insults. While speaking to CNN Thursday, Trump called Rubio a "kid." Later the same day, Rubio was speaking with a Kentucky sports radio station when he made his remarks about Trump.

"[Trump] takes shots at everybody that gets anywhere close to him, in terms of a poll, or anytime he hits a rough spot, that's what he does," Rubio said. "He had a really bad debate performance last week, he's not well informed on the issues, he really never talks about issues and can't have more than a 10 second sound bite on any key issue."

Both Trump and Rubio are campaigning to win the Republican primary election, which will give them the right to campaign to be President of the United States of America in 2016.

"He's a very touchy and insecure guy so that's how he reacts," Rubio said of Trump, according to The Hill. But Trump had plenty fo say about Rubio hours before.

"He's got the worst voting record in the United States Senate," Trump said during his appearance on "New Day" on CNN. "He shouldn't even be running in this race as far as I'm concerned...He's a kid."

Rubio is 44. Trump is 69. Trump's wife, Melania Trump, is 45. A recent poll from Fox News shows that Rubio is tied for third place in the primary race. The numbers show Rubio getting nine percent of the vote along with Carly Fiorina, according to Fox News. Trump has been the frontrunner in the polls.