The Iowa Senate race between Republican Joni Ernst and Democrat Bruce Braley is a dead heat, according to a Quinnipiac University poll released Monday. The poll is wildly different from a Des Moines Register survey from Saturday that found Ernst seven points ahead.

Ernst and Braley are tied at 47 percent with 4 percent of Iowa voters undecided, according to the Quinnipiac poll. A Quinnipiac survey from Wednesday showed Ernst leading Braley by four points, 49 to 45 percent.

"Iowa's U.S. Senate race is a dead heat. The candidate who best gets his or her folks to the polls is going to win," said Peter A. Brown, assistant director of the Quinnipiac Poll.

Just a few days earlier, the Iowa poll conducted on behalf of the Des Moines Register showed Ernst leading Braley 51 percent to 44 percent. The advantage was Ernst’s biggest of the campaign.

"This race looks like it's decided," said J. Ann Selzer, the pollster who conducted the survey for the Register. "That said, there are enormous resources being applied to change all that."

The seat is currently held by Sen. Tom Harkin, a Democrat who is retiring. Real Clear Politics ranks the race as a toss-up, with Ernst leading by an average of 1.4 percentage points in the latest nine polls.

Harkin, who is backing Braley, stirred controversy in the race after video of him comparing Ernst’s looks to Taylor Swift was published Sunday by BuzzFeed.

“In this Senate race, I’d been watching some of these ads. And there’s sort of this sense that, ‘Well, you know, I heard so much about Joni Ernst. She is really attractive and she sounds nice,’” Harkin said during a barbecue held in his honor. “Well, 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 [Minnesota Rep.] Michele Bachmann, she’s wrong for the state of Iowa.”

Ernst took offense at the remarks, saying Harkin wouldn’t have brought up her looks if she were a male candidate.

"I was very offended that Sen. Harkin would say that. I think it's unfortunate that he and many of their party believe you can't be a real woman if you're conservative and you're female," Ernst said on “Fox and Friends” Monday morning. "I believe if my name had been John Ernst attached to my résumé, Sen. Harkin would not have said those things."