The case against the electoral college:
1. It's unfair to voters in larger states.
An electoral college vote in Wyoming represents 200k people. An electoral college vote in California is worth 725k people. A person is a person. Everyone's vote should count equally, and right now it isn't counted equally. If I moved to California right now, my vote would be less valuable. Land can't vote. Where people live should be irrelevant. If the electoral college was actually proportionate, a lot of my issues would go away.
And fwiw, I do recognize the value of giving smaller states more leverage, that's why I support the senate. The President should be representative of what the majority of Americans want.
2. Electors don't always vote for the candidate that they should vote for.
Clinton ended up getting 227 electoral votes instead of 232. She lost 3 votes to Colin Powell, one to a Dakota Pipeline protester, and one to Bernie. Trump lost two votes to Rand Paul. This is pretty irritating, and could make corruption easier in the end since the majority of Americans opinions don't matter.
3. Why it was created.
The electoral college was created to give more power to small states. I would argue that a main reason for this is to protect slavery, and several historians would agree with me. I don't buy the argument that without the electoral college, a tyrant could come to power. Most 'tyranny of the majority' arguments are rooted in the idea that there is a 'real America' (you may differ on this). I live in semi-rural Kansas. If we are the real America, then America is ******.
4. Likely elimination of battleground states.
If I'm in Ohio, Michigan, Florida, Pennsylvania, etc. I am extremely frustrated with the fact that every four years, politicians come in and promise the world to me, leave with my vote, and come back four years later and do it all over again. You might say that in a popular vote system, politicians would only campaign to large hubs of people. I say GOOD! I would much rather politicians campaign to where the people are instead of where the electoral votes are.
And it isn't like candidates campaign to small states today. They don't.
5. State winner take all.
This is a minor issue for me personally, but under this system, you can win while getting less than a third of the votes. That's pretty silly.