The Electoral College was designed so the large populous States would not be able to "control" everything.
If it was a matter of strictly "popular vote", there would never be a presidential candidate go to Iowa or New Hampshire (which are the first 2 primaries presently). Only California, New York, Texas, Florida, Illinois, Pennsylvania, and Ohio would matter. F*ck Wyoming, Rhode Island, etc.
The Congress is "balanced" in the same way. The Senate has two senators from each State regardless of population, but the House of Representatives has members from each State based on population. California has 53 Representatives as it is the most populous. Alaska, Delaware, Wyoming each only have 1 Representative (but still 2 Senators).
Thus any law must pass BOTH houses of Congress. So in the Senate all States have equal representation. In the House, each States is represented by population. The Senate has always been the more powerful of the two bodies.
The Electoral Collage is based on the number of Senators + Representatives. Each State has the same number of vote on the "Collage" as they have Senators + Representatives. (California 55, Alaska 3, etc). In most States the candidate who wins the popular vote receives ALL of the EC votes. So winning 51% of California voters gets you all 55 EC votes. (Only Maine and Nebraska prorate EC votes.) California is overwhelmingly Democratic (as is New York) and those votes always go to the Democrat. Hillary won California by 61% of the popular vote in 2016). Thus, any GOP candidate has to win overwhelmingly in the rest of the States.
Here's a map of RED (GOP) vs BLUE (Dems) States for 2016