Vermont Sen. Bernie Sanders told the crowd at Central High School in Phoenix Sunday that the presidential race is not a personality contest.
Stumping for Hillary Clinton, Sanders attacked Donald Trump on everything from wanting to ban Muslims to global warming.
"He thinks that climate change is a hoax coming from China," Sanders said.
PolitiFact fact-checked this claim when Clinton said it back in June. They found that Trump did tweet that view in 2012.
The concept of global warming was created by and for the Chinese in order to make U.S. manufacturing non-competitive.
— Donald J. Trump (@realDonaldTrump) November 6, 2012
And while he now says that tweet was a "joke," he still believes climate change is a hoax.
So they rated this claim "mostly true."