I thought she was the one who understood economics?

Without the full context it's hard to evaluate, but this latest idea from Hillary demonstrates all the sophisticated populist economic thinking of a 4th grader from Arkansas. Or a Democrat in an election year.

Instead of giving every baby $5000 for college, what would happen if we gave every one $5000 for a car? The price of all cars would go up $5000. Everyone has $5000 more to spend that they didn't earn, everyone's willingness to pay should go up $5000, so prices can go up $5000 with no impact on unit sales volume. Car dealers all say "thanks for the extra profit". It would be little different for universities.

Yes, some folks who used to have $0 for school and hence weren't in the market would enter, creating demand at the lower end of the willingness to pay distribution. But we're essentially just adding an appreciated $5000 to the entire willingness to pay distribution for college, which just means that prices should go up accordingly, and no one is any better off, save the providers of college education, who can charge more for the same product and hence earn more money.

I'm astounded that the problems with this approach aren't obvious to everyone, including she who laid it out there.

It's her willingness to say populist and dumb things that I have to believe she's smart enough to know are populist yet dumb which makes me not like her. She's saying what she thinks she needs to say to get elected, not what she thinks is true. Which means power, not policy is her end goal. I'm not voting for that.