Donald Trump talks about Hillary and Bill Clinton on Friday. Trump: Maybe Hillary wants to 'keep her eye' on Bill

When it comes to Hillary Clinton saying she would put Bill Clinton in charge of economic issues in her administration, Donald Trump has a few theories as to why.

"I don't know. Maybe he'll bring the 'energizer' with him," Trump said on "Fox & Friends."


Co-host Steve Doocy asked, "Who's the 'energizer'?"

Trump previously used the term in a tweet on Wednesday. Former Secret Service agent Ronald Kessler wrote that agents gave Clinton's mistress that nickname, though Trump did not explain, going on to hit the former president for signing NAFTA and causing the boom in subprime mortgages that led to the recession.

"Don't you think he -- she is saying I'm going to put him in charge of that because people like him more than they like her?" Doocy asked.

"Well, maybe she's saying that or maybe she just wants him around the White House so she can keep her eye on him," Trump said.