I would think you (generically) would have learned that polling data in this election particularly is not overly reliable  :-)

I'm not sure Comey is the one who particularly motivated the Rust Belt - didn't hurt, but I don't think he was the driving force.  From what I've read - it was jobs and economics that motivated them to turn out as they did.  

"In the end, the bastions of industrial-era Democratic strength among white working-class voters fell to Mr. Trump. So did many of the areas where Mr. Obama fared best in 2008 and 2012. In the end, the linchpin of Mr. Obama’s winning coalition broke hard to the Republicans."
http://www.nytimes.com/2016/11/10/upshot/why-trump-won-working-class-whites.html