I live in Illinois, where it was well-known that Mrs. Clinton's votes would far outnumber Mr. Trump's.
This fall, I did not see any Trump-for-president ads on local TV or in local newspapers. Perhaps the absence of Trump ads was to be expected, because the Trump campaign saw no electoral-vote gain by advertising here.
But I saw MANY Clinton-for-president ads. If Trump ads would not affect electoral votes, then why would Clinton ads?
One could argue, even without the benefit of hindsight, that the Clinton campaign was wasting ad dollars in Illinois. But my view is that Clinton did expect non-Illinois electoral votes from advertising IN Illinois because of the campaign donations that it would induce.
Of course Trump supporters are arguing that Mr. Trump would have won the popular vote, if it were the relevant metric, because he would have campaigned differently.
But my point here is different: that the popular vote is an indicator of campaign style. The Clinton campaign's style was campaign-cash intensive and EVERY state's cash is valuable even in an electoral-college contest. As long as eliciting donations is correlated with eliciting votes, the campaign-cash intensive candidate should be getting a lot of votes in non-swing states.
The Trump-campaign's style was rally intensive. It's more difficult to move, say, an Illinois rally's results to Ohio than it is to take Illinois cash to buy Ohio ads. So it's no surprise that the rally-intensive candidate focused his appearances in the swing states whereas the cash-intensive candidate campaigned more nationally.