Politifact is blatantly biased. Bernie and Trump made the same claim about african american youth unemployment, and they rated Trump a liar and Bernie honest [0][1].
The primary difference there appears to be that the Sanders campaign answered a request for where their numbers came from with references, and the Trump campaign did not respond, leaving the (different) author to attempt to research the topic themself.
The Sanders article they published dates almost a year before the Trump one... They should have found their own article if they attempted serious research
[0]: http://www.politifact.com/truth-o-meter/statements/2015/jul/... [1]: http://www.politifact.com/virginia/statements/2016/jun/20/do...