Why is Taylor Swift part of the Iowa Senate race?

Pop star Taylor Swift generates plenty of her own headlines for her music, but she's also entered the national political conversation by way of the Iowa Senate race.

Retiring Iowa Sen. Tom Harkin, a Democrat, invoked swift when talking about why he wouldn't support Republican candidate Joni Ernst in the upcoming midterm election.

"In this Senate race, I've been watching some of these ads. And there's sort of this sense that, 'Well, I hear so much about Joni Ernst. She is really attractive, and she sounds nice,'" Harkin said at an event for Story County Democrats, according to Buzzfeed, which obtained video. "I got to thinking about that. I don't care if she's as good looking as Taylor Swift or as nice as Mr. Rogers, but if she votes like Michele Bachmann, she's wrong for the state of Iowa."

The comment didn't sit well with Ernst, who told CBS News Affiliate KCCI, "It's very unfair for someone who is sitting in a United States senatorial seat to say he's supportive of everyone regardless of gender, but he's not. I can be a strong conservative woman and still be a good leader."

She took care not to insult Swift's legions of fans, though. On Monday morning, Ernst tweeted, "Excited to see @taylorswift13 in Des Moines on October 8th next year on her #1989Tour."

Harkin eventually apologized Monday, saying in a statement, ""I shouldn't have said those things, I know that. I regret anytime someone feels offended by what I have said."

"But I am only human and I can make mistakes sometimes in how I say something. In fact, I have complimented her on running a very good campaign," added.