She begins her dismantling by addressing Romney's now infamous dismissal of 47 percent of the electorate who supposedly pay no taxes (emphasis mine):

The central problem revealed by the tape is Romney’s theory of the 2012 election. It is that a high percentage of the electorate receives government checks and therefore won’t vote for him, another high percentage is supplying the tax revenues and will vote for him, and almost half the people don’t pay taxes and presumably won’t vote for him.

My goodness, that’s a lot of people who won’t vote for you. You wonder how he gets up in the morning.

This is not how big leaders talk, it’s how shallow campaign operatives talk: They slice and dice the electorate like that, they see everything as determined by this interest or that. They’re usually young enough and dumb enough that nobody holds it against them, but they don’t know anything. They don’t know much about America.

We are a big, complicated nation. And we are human beings. We are people. We have souls. We are complex. We are not data points. Many things go into our decisions and our political affiliations.

You have to be sophisticated to know that. And if you’re operating at the top of national politics, you’re supposed to be sophisticated.

[...]

You know what Romney sounded like? Like a kid new to politics who thinks he got the inside lowdown on how it works from some operative.