This reply actual cements the underpinnings of the electoral college.
You are exactly right...candidate often consider a state decided.
They focus their campaigns on undecided states.
And that's the point.
The state of New Hampshire (pop. 1,321,672) is just as important as the state of California (pop. 36,580,371) in a close presidential election.
The electoral college protects the voice of the smaller states from being completely drowned out by a few large states.
Or the Midwest states being overwhelmed by the Eastern states.
If we had a unitary government system, a popular vote would be the order of the day...but we do not.
The United States was designed to be a federal government system.
A federal government system is the common government of a federation...in our case a federation of states.
Understanding that will go a long way to explaining our system to your colleagues overseas.
They live under a unitary government...you do not.
but that's the problem. There is no real interest in those decided states or their voters. Therefore because California is "Decided", they aren't trying to get those votes of the 36 million people because that state has been pretty reliably Blue since 1992. So those 36 million get ignored while all this attention is lavished upon the 1.3 million in NH.
One man, one vote. that means they are going out and fighting for every vote in every state.
Incidently, even the founding fathers expected most elections to be decided in the House. They specifically designed the system to throw most elections there, until they realized how cumbersome that was after the 1800 election when Aaron Burr tried to usurp Thomas Jefferson's victory.
Every time the EC has produced a result opposite of what the will of the voters was, it was turmoil.
John Quincy Adams was accused of having been elected in a "Corrupt Deal" when Andrew Jackson's victory was ignored by the House after the election was thrown there in 1824.
Rutherford B. Hayes was called "His Fraudelancy" after a commission appointed to sort out disputed state victories in 1876 gave him the presidency after John Tilden won the popular vote.
Benjamin Harrison won in 1888, despite losing the electoral vote. The voters threw him out in 1892 and put Grover Cleveland back in.
And in 2000, you had George W. Bush, whose presidency was never accepted by half the country after the Supreme Court decided the election in his favor.
It's a bad system, and it should be scrapped.