there's also the fact that electoral college votes are not proportional to population. texas has 48 times the population of wyoming but only gets 12 times the number of votes in the EC.I'll take a crack at this.
So we have a system called the Electoral College. In a real sense, the president is not determined by who got the most citizen votes nationwide - the popular vote. Instead, it's decided by who got the most 'elector' votes from the Electoral College.
Here's how the Electoral College works:
Any given state in the USA has a number of electors, determined mathematically by the population, which itself is determined by the census. North Dakota has 3 electors, whereas California has 55. My home state of South Carolina has 9. Every state looks at which candidate won the popular vote in their own state, and then ALL of the electors for that state will vote for that candidate. There are a couple states that work a little differently and there are some historical and legal asterisks to this, but for the sake of keeping it simple, that's basically how it works.
Here's the 2016 map of electoral college votes:
So, if you win the popular vote in texas by 4 million votes, you get 36 electors. If you win the popular vote in texas by 13 votes, you get...36 electors. So you can start to see how the electoral votes in any given state doesn't necessarily represent how the popular vote came down in that state.
So we have a situation currently where a significant number of democratic voters are more concentrated in certain states. States like California, Oregon, Washington and others tend to vote overwhelmingly blue, but they'd get the same number of electoral college votes even if hundreds of thousands of blue voters stayed home, as long as they still technically got the most votes.
votes in a low-population state literally count for more than higher density states.