There is nothing to figure out with what went wrong with the Democractic strategy in 2016. 

Hm. Let's see what went wrong?

If I was an FBI profiler what would I target to defeat a strong DNC strategy?

I know I'd attack Hillary Clinton's credibility. That would work and guess what? It did. 

Do you Comey only  became an Independant in 2016? No? Until 2016 he was a Republican. All of a sudden in 2016 he had a rush of conscience and became an Independent.

Indeed.