I was talking about Whites' relative turnout. Was it not clear? It felt in a much higher rate than demographics (especially in 2012)
So was I. The 'missing white voter' theory is basically how there are a bunch of white voters out there who didn't vote in 2012 and could help a Republican out if they all went and voted. I think it's a bit silly though. As numerous analyses have stated, many of these voters are in safely red or blue states, and even if they all came out of the woodwork, they are not all going to vote for Trump/Republicans. It wouldn't have been enough to save Romney and it wouldn't be enough to save Trump.
Then you have to factor in that Trump is relying more heavily on white working class voters, who have lower turnout rates than college educated whites. Particularly white working class men, again, Trump's strongest cohort (?). Depending so much on low-propensity voters while having no suitable GOTV effort is awful strategy. For this reason it's quite
possible that Trump under-performs more than he should have, as he is relying on voters who may or may not show up despite answering those pollsters. Or they could show up in force, I dunno. I wouldn't bet on it, though.