Democratic vice presidential nominee Tim KaineTimothy (Tim) Michael KaineLiberty University professor charged with alleged sexual battery and abduction of student Senate parliamentarian looms over White House spending bill Menendez jabs State official over Colombian group's terror designation MORE came to the defense of Hillary ClintonHillary Diane Rodham ClintonRepublican Ohio Senate candidate slams JD Vance over previous Trump comments Budowsky: Why GOP donors flock to Manchin and Sinema Countering the ongoing Republican delusion MORE's family foundation, flipping a recent line of attack from Donald TrumpDonald TrumpBaldwin calls Trump criticism following 'Rust' shooting 'surreal' Haley hits the stump in South Carolina Mary Trump files to dismiss Trump's lawsuit over NYT tax story MORE against him. 

Kaine, addressing the annual conference of Iron Workers International in Las Vegas on Monday, hit Trump for attacking the Clinton Foundation while details of the GOP presidential nominee's own finances remain scarce.
 
"The Clinton Foundation is a nonprofit organization that is a world-class charity that's provided lifesaving AIDS drugs," Kaine said.
 
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"Before you go out attacking a charity, why don't you come clean about your own business dealings? Why don't you tell us who you are in debt to?"
 
Kaine stressed that the nonprofit discloses its donors, and he echoed accusations that the billionaire is hiding something in his tax returns, which he has refused to make public. Kaine and Clinton released a new batch of tax information several weeks ago. 
 
Trump and other Republicans have been vocal critics of the Clinton Foundation, accusing the Democratic nominee of running a pay-to-play scheme because the foundation took money from foreign entities while she served as Secretary of State. 
 
On Monday, the GOP nominee called for the foundation to be "shut down immediately." 
 
While the foundation has said it will not accept foreign donations if Clinton is elected president, other arms of the organization could continue to so, according to reports. 
 
During the speech, Kaine questioned why Trump hasn't expanded on his business dealings to provide a fuller picture to the public, pointing to recent news reports that found Trump holds at least $650 million in debt to backers including the Bank of China and Goldman Sachs. 
  
"He's at the center of a vast global web of financial relationships," Kaine said. "We've got to know who Donald Trump is beholden to because we don't want to be tricked by Trump."
 
Noting that the real estate magnate has bragged about how he uses the system to pay as little in taxes as possible, Kaine also laid into Trump for not paying into America's defense and civil services.
 
"Nobody here likes paying taxes — I don't like paying them. But where does the money go? It goes to our troops. ... It's a responsibility, it's a patriotic duty. We are citizens of an extraordinary nation, and that's the deal," Kaine said at the convention.
 
Kaine said he's one of two active senators with a child serving in the military. 
 
"Who supports our troops? Taxpayers. Who supporters our veterans? Taxpayers. Who supports our police, firefighters, teachers and public parks? Taxpayers," he said. 
 
"You want to say you'll be great for the veterans? Donald Trump has been stiffing our troops, veterans, teachers, police and firefighters his whole life, and now he says he's suddenly going to be great?"