California.
Texas.
New York.
Florida.
Illinois.
Pennsylvania.
Ohio.
Michigan.
Georgia.
North Carolina.

These are the top ten populous states. According to Wikipedia, they represent 53.42% of the USA's population.

The Democrats currently have as their front-runner a man who couldn't win seven* of them. A man who couldn't win two of the three reliably Blue states**. A man who won none of the four*** that are generally considered to be battleground states this year.

But hey: he won Idaho and Wyoming, right?

*CA, FL, MI, NY, OH, PA, TX
**CA, NY, IL
***FL, MI, OH, PA