海角大神

An Obama-Romney rematch is brewing in Iowa. Well, sort of.

Former GOP presidential candidate Mitt Romney and first lady Michelle Obama are headed to the state to stump for Senate hopefuls. With less than a month to go before election day, Democratic Rep. Bruce Braley and Republican Joni Ernst are聽locked in a nail-biting toss-up聽for an open Senate seat.

Control of the Senate hinges on Iowa and a handful of other competitive contests. The latest聽聽gives Ms. Ernst a tenuous 1.5 point advantage. Each candidate is hoping star power 鈥� in the form of a popular first lady and a Republican standard-bearer 鈥� can swing a few votes in moderate Iowa.

But don鈥檛 hold your breath. The race is likely to remain a toss-up, no matter what Ms. Obama or Mr. Romney do.

鈥淭here鈥檚 really not a lot of evidence that any kind of endorsements really sway a large number of voters,鈥� says Dianne Bystrom, director of the Carrie Chapman Catt聽Center for Women and Politics at Iowa State University in Ames. 鈥淲hat they tend to do is really just shore up partisan support that you already have.鈥�

Big names like Romney and Obama excite party faithfuls, but won鈥檛 necessarily sway undecided voters. Around聽聽say they remain 鈥渦ndecided鈥� in recent polling. But Bystrom says that 鈥測ou kind of wonder if they are really undecided, or just don鈥檛 want to tell the pollster鈥� who they鈥檙e voting for.

鈥淚 don鈥檛 know of one undecided voter in the Braley-Ernst race. Not one,鈥� Bystrom says.

Mrs. Obama 鈥� visiting today 鈥� and Mr. Romney 鈥� flying in next week 鈥� are darlings of their respective parties. Neither has the baggage of being in office, and despite her husband鈥檚 spiraling approval ratings, Obama remains a popular figure. And with the race so tight, Braley and Ernst are willing to try anything.

Star power has gone to bat for candidates in other key races as well, including a closely watched Senate race in Kentucky. There, Democrat Alison Lundergan Grimes is trying to unseat Senate minority leader Mitch McConnell. Romney and former President Clinton聽both jumped into the competitive race聽last week, hoping to tip the scales in their party鈥檚 favor.

According to Bystrom, however, endorsements and star power only sway voters when there鈥檚 a dearth of information about candidates. That鈥檚 not the case in the Hawkeye state, where ads flood the airwaves and contrasts between the candidates are generally clear.

鈥淭his campaign is a high information campaign,鈥� Bystrom says, meaning voters likely know all they need to know about their two options. 鈥淗ow you could be undecided at this point in the election is really pretty interesting."

The race has gotten bruising as it's tightened in the past few months. Earlier in the campaign, Democrats were counting on a win in Iowa as part of their strategy for maintaining control of the Senate. When Ernst won the GOP primary, Democrats鈥� calculus had to change.

鈥淏raley as a candidate was expected to be strong: a sitting congressman running against a fairly unknown person,鈥� Tim Hagle, a political science professor at the University of Iowa,聽told聽the Monitor last month. 鈥淏ut Braley lost that edge through a number of mistakes.鈥�

As Braley has struggled with gaffes and missteps, Ernst has relied on her down-home image to appeal to voters. Ernst has touted her credentials as a farm-raised mother and Iraq war veteran to win strong support among rural Iowans.

Braley is trying tarnish Ernst鈥檚 appeal by blasting her on women鈥檚 issues. Those attacks, Democrats hope, could bolster the lead he already holds among women voters.

鈥淛oni Ernst, too extreme for Iowa,鈥� says one anti-Ernst attack ad, paid for by the Democratic Senatorial Campaign Committee. The ad details Ernst鈥檚 support for a fetal personhood amendment to the Iowa constitution.

"This election is about a clear choice between moving Iowa forward or following a radical tea party agenda that's going to take us backwards," Braley 聽during a debate last month.聽

The Ernst campaign is "confident those attacks will fall flat against a strong, independent woman and mother like Joni,"聽聽spokeswoman Gretchen Hamel.

Staff writer Francine Kiefer contributed to this report.