[dragonwriter]

> Why is this a big campaign issue?

It's a big campaign issue (for Warren, and simultaneously not really a big campaign issue otherwise) because Warren is far behind the leading candidates, in a distant third or fourth place depending on the poll, so she's trying to use big concrete policy proposals like this to gain traction.

> Why not break up Walmart while we're at it?

She has other policies that would target Walmart, too.