538 isn’t even close... They aggregate polls from weeks ago with current polls... Look at the last 6 FL polls. All but 1 are Trump, 1 is tied, yet Hillary is projected to win.
I think 538 has a very reasonable prediction based on the polling about two weeks ago- which is pretty much what they’re ‘selling’.
As someone above says: it’s the bad polls that make the aggregators inaccurate. “Likely voters” polls have used either the respondent’s word on how likely they are to vote- which is known to be very inaccurate, or they have used 2012 exit polling data- which there is no justification for doing.
BTW: The highly liberal and Trump-hating children at PEC have a map with their prognosis http://www.270towin.com/maps/princeton-election-consortium that can be changed by the user to reflect reality. It is very useful.