Still in the vein of U.S. turnout, I decided to try adding 10% of non voters to either side in the 2012 presidential election. For comparison I also tried removing 10% of Obama's OTL votes vs 10% of Romney's.
The result is very interesting. It shows how ingrained the US electoral college setup is with margins shifting considerably across the nation but only impacting the actual result in a handful of states. (I have ignored Nebraska and Maine's split EVs for simplicity). It also shows the effectiveness of Obama's Blue Wall strategy. Obama could lose 10% of his OTL votes (bottom left map), lose Ohio, Florida and Virginia, lose the popular vote across the USA, and yet still narrowly win in the electoral college (now wouldn't
that have been fun...)
However this also works the other way - Obama effectively maxed out what he could achieve in OTL and only one state, North Carolina, is actually flipped from Republican to Democratic either by giving 10% of OTL non-voters to Obama (top left map) or taking away 10% of Romney's OTL voters (bottom right map). Having said that, in the first case Georgia and Arizona both come close to flipping, but don't quite make it.
It's worth remembering that when it comes to adding OTL non-voters, 10% represents a lot more people in the states with low turnout than the ones with high turnout - so for example Nevada and the South are more impacted by it than the higher-turnout states of the Upper Midwest. In fact this renders the latter a very resilient part of Obama's Blue Wall and shows that even though they may look close on OTL maps at first glance, it shows how laughable for the foreseeable future the idea is that the Republicans could break into Minnesota, Wisconsin and Michigan (or even Iowa) is as some have suggested - at least with anything even vaguely resembling the current battlefield and coalitions. The same is true of New Hampshire, Colorado and to a lesser extent New Mexico.
The only way Romney wins here is if he engages 10% of OTL non-voters with his charisma and unique appeal (stop laughing at the back there) as in the top right map, where he flips not only Florida, Ohio and Virginia, but also Pennsylvania and Nevada. Even then it's not what one would call a crushing electoral college victory but it is a victory - and shows how hard a climb any conventional Republican candidate facing any conventional Democratic candidate has at present.
Of course, that's not what's actually happening, is it...