"I think Elizabeth Warren is very smart, and anybody who's listened to him and how he's talked certainly could draw that conclusion," Clinton said. 
"I'm going to let people judge for themselves, but I have the highest regard for Sen. Warren."
Clinton repeatedly slammed Trump as a “loose cannon,” calling him too dangerous to be president.
"I've seen the presidency up close from two different perspectives, and I think I know what it takes," she said. 
"I don't think we can take a risk on a loose cannon like Donald Trump running our country."
Clinton pointed to Trump's suggestions that more countries should have nuclear weapons and that wages are too high in America, as well as his pledge to ban Muslims from entering the U.S. and his changing position on abortion.
"He's the one who ran a campaign insulting people, demeaning women, degrading people with disabilities, talking about keeping Muslims out of the country," she said. 
Ahead of a likely general election match-up with Clinton, Trump has repeatedly said that he hasn't started to really dig in attacking Clinton yet, having previously bashed her and President Bill ClintonWilliam (Bill) Jefferson ClintonBiden painted into a basement 'Rose Garden strategy' corner Giuliani says Black Lives Matter is 'domestic terrorist' group We have the resources to get through this crisis, only stupidity is holding us back MORE for his infidelity. 
But when asked whether she was concerned about those attacks, Clinton laughed and told Trump to bring it on. She added that she'd be able to push back on him like his GOP rivals could not because she has stark disagreements with him on the issues. 
"If he wants to go back to the playbook of the 1990s, if he wants to follow in the footsteps of those who had tried to knock me down and take me out of the political arena, I'm more than happy to have him do that," she said. 
"This to me is a classic case of a blustering, bullying guy who has knocked out all of the Republicans because they were just dumbfounded. They didn't know how to deal with him and they couldn't take him on on the issues because they basically agreed with him."
The interview with CNN was Clinton's first public appearance since Trump became the presumptive GOP presidential nominee.