Democratic presidential hopeful Martin O'Malley said Republican presidential candidate Donald Trump is not as tough as he appears and is just attacking people weaker than him. 

The former Maryland governor talked with MSNBC's José Díaz-Balart about Trump's impact on the 2016 presidential race, as the real estate businessman has gained a lot of popularity in recent weeks.

"If Donald Trump is such a tough guy, why is it that he takes on minimum wage earners?" O'Malley asked. "Why is it that he says denigrating things about new immigrants and about women? I don't find anything tough about Donald Trump at all."

Trump has talked about Mexican immigrants during his presidential launch calling them "rapists" and "criminals." He vowed to build a wall between the U.S. and Mexico to "keep the illegals out" should he win the ticket to the oval office.

Despite his "racist" remarks against undocumented immigrants, Trump has risen in the spotlight and is currently gaining support from many Republicans.

O'Malley said people are intrigued by Trump because they are currently in a bad economic state, making less than 70 percent of what they used to earn 12 years ago.

"We've seen this in history where people believe they cannot give their children a better future, it becomes a very volatile political climate ... where leaders can scape goat other people and say 'the reason that you're not doing better is because of people not like us,'" O'Malley said.  

O'Malley added that Trump is "weak" for trying to scapegoat other people.

Meanwhile, Trump called O'Malley "a disgusting, little, weak, pathetic baby" for apologizing for a comment he made about the Black Lives Matter movement, Politico notes.

When O'Malley was giving a speech at Netroots Nation last month, a group of protesters repeatedly shouted, "black lives matter."

The Democratic presidential candidate responded, "Black lives matter. White lives matter. All lives matter." He later apologized because people felt that he was insensitive to the whole Black Lives Matter movement in making that comment.