The open race for U.S. Senate in Iowa is all about hogs and chicks right now. Yes, really.

Here's the situation: Rep Bruce Braley, the Democratic nominee, released a TV ad Wednesday called "Peep." The point of the commercial was to criticize Republican nominee Joni Ernst for not doing enough to curb spending in the state Senate. The ad contrasts her record with a tough-talking ad about castrating hogs and cutting spending the Republican released earlier this year.

"We've all the heard the one about pigs squealing. But when Joni Ernst had the chance to do something in Iowa we didn't hear a peep," the narrator says as an image of a young bird flashes onscreen.

The ad prompted criticism from on Twitter from Ernst adviser David Kochel, who implied that if a Republican used the same ad, that person would be criticized for sexism:

The National Republican Senatorial Committee said Braley should be "embarrassed" by the ad. Braley's campaign responded that the lack of GOP complaints about the commercial's policy points proves the ad's criticisms are valid.

"That we still haven’t heard a peep from state Sen. Ernst’s campaign on the substance of our ad shows just how clearly her record does not live up to the image she's portraying on TV. The facts matter, and the truth is, state Sen. Ernst talks a lot about cutting pork, but her actions are something else entirely," said Braley campaign manager Sarah Benzing.

Of course, the whole dustup wouldn't be happening if not for Ernst's ad, "Squeal," which introduced her to voters at a time the Republican primary was still unsettled. It was a play for earned (read: free) media attention -- the ad was initially backed by only a small TV ad buy -- and it got plenty of it. Late night hosts even mentioned it in their sketches and monologues.

"I grew up castrating hogs on an Iowa farm. So when I get to Washington, I'll know how to cut pork," Ernst said in the commercial released in late March. At the end of the spot, Ernst concluded, "Washington's full of big spenders. Let's make 'em squeal."

According to the Des Moines Register, Democratic state Sen. Steve Sodders, in an effort to give Braley some back-up, characterized hog castration as "mutilating animals." Ernst's campaign hit back with a call for Braley to apologize for his "repeated insults to Iowa farmers," a reference to Braley's remark earlier this year that Sen. Charles E. Grassley (R-Iowa) is a "farmer from Iowa who never went to law school."

So, that's the story of how the Iowa Senate race became all about hogs and chicks. (As promised in our headline!)

But what does the entire episode say about the race? There are two big takeaways.

One is that Ernst -- the choice of both the establishment and tea party who cruised to victory in Tuesday's primary -- is clearly a threat to win and is not being taken lightly by Democrats. The fact that Braley's campaign hit her with a negative ad on the first day of the general election campaign is evidence of this.

Second, Ernst's record as a state senator is going to come under heavy scrutiny from Democrats. She's sought to introduce herself in personal terms as a mother, a soldier and a fierce opponent of business as usual in Washington. But Democrats plan to use her legislative record to say, "Hey, her rhetoric does no reflect her results."