Florida was decided by 73,000 votes in 2012
North Carolina - 79k
Virginia - 116k
Wisconsin - 190k
Ohio - 100k
http://elections.nbcnews.com/ns/politics/2012/all/president/
A bit over a half million votes in 5 swing states could have changed the world
How many with small margins? Certainly in 2012 just enough. Perhaps your memory is poor. Mine isn’t.