The way the electoral voting system works, if you don't live in a swing state, does the popular vote even matter?
Every vote matters.
yes it matters
No. If you are from Texas your vote for President is irrelevant.
The vote matters. If it didn't, why even vote at all? If everyone on one side or another sat home, you would see what a difference one vote would make.
It matters because undecided voters watch the election polls carefully.