The point is that the Electoral College system motivates the candidates from the major parties not to move to the center of the country. Instead, they should and must focus only on what drives turn out in a handful of states that are not necessarily representative of the rest of the nation.
Here a New York Times columnist plumps for anyone but the incumbent, but misses the point of what the system causes to happen:
“A majority of the American electorate — liberals, moderates and even some conservatives — want a greater government role in health care, a higher minimum wage, higher taxes on the rich and less punitive border policies. If Trump isn’t going to move to the center, then their only choice should be the party that, no matter its nominee, backs each item on that list.”