Earlier quoted context omitted.
A purely popular vote system has its own flaws. In particular, national elections would be reduced to politicians catering to voters in a few high-density regions rather than attempting to appeal to a geographically dispersed electorate.
Most of the country doesn't live in high-density areas. If you only catered to urban voters, you'd lose in a huge landslide.
Suddenly, U.S. transportation & communications infrastructure problems make a lot more sense. I knew the U.S. was a big place, but I vastly underestimated how spread out our population was.