Representative Michele Bachmann is replacing the top two national figures in her presidential campaign, as the latest Rasmussen poll of Iowa Republicans shows the largest lead yet for Texas Governor Rick Perry.

Ed Rollins has run Bachmann’s campaign since June, but he confirmed yesterday that he will be a “senior adviser” going forward.

Rollins, who’s 68 and had a stroke a year and a half ago, cited health reasons for his decision.

“I just don’t have the endurance to go 12 to 14 hours a day, seven days a week anymore,” Rollins told CNN’s Anderson Cooper on Monday. […]

“Ed is moving away from the demanding day-to-day operations of the campaign and into a serious advisor role,” press secretary Alice Stewart said in a statement. “He is fantastic and will continue to be invaluable on the campaign.”

Late Monday night, Bachmann’s team announced Keith Nahigian, current campaign strategist, as the new interim campaign manager.

Politico’s Maggie Halberman broke the news yesterday that David Polyansky is out as Bachmann’s deputy campaign manager:

“I wish Michele nothing but the best, and anyone who underestimates her as a candidate does so at their own peril,” Polyansky told POLITICO.

But a GOP source familiar with the situation said that Polyansky had “strategic differences on the path forward” with the candidate, who has struggled to gain traction in the last few weeks.

Rollins clarified, “There’s no strategic differences in the sense of what we should be doing or saying — it’s just a question of how you use your time, how you use your resources.”

I haven’t seen any reports yet of leadership changes in Bachmann’s Iowa campaign, chaired by State Senator Kent Sorenson. I will update this post with further developments if the shakeup extends to Bachmann’s Iowa staff, or if details emerge on how Polyansky favored allocating resources to deal with Rick Perry’s huge momentum in the GOP presidential race. For now, Bachmann is focused on Iowa and South Carolina, not so much New Hampshire.

Yesterday Rasmussen Reports released the numbers from its latest Iowa poll, conducted August 31. Perry leads with 29 percent support among “those likely to participate in the Iowa GOP Caucus.” Rasmussen’s screen for likely caucus-goers is not clear from the published results, but Perry’s lead is outside the poll’s margin of error of plus or minus 3 percent. Bachmann, former Massachusetts Governor Mitt Romney and Representative Ron Paul form the second tier in Rasmussen’s results, receiving 18 percent, 17 percent and 14 percent support, respectively. The rest of the field is way back: 4 percent for former U.S. Senator Rick Santorum and former Godfather’s Pizza CEO Herman Cain, 3 percent for former Utah Governor Jon Huntsman, and 2 percent for former House Speaker Newt Gingrich. Scott Rasmussen notes,

However, just 27 % of all likely Iowa caucus goers are certain of how they will vote. That leaves plenty of room for opinions to shift, particularly if new candidates enter the race. Perry has entered the race on top but has yet to face a debate or other serious campaign testing from his competitors. That will change with a large number of candidate forums scheduled during the month of September.

Speaking to CNN yesterday, Rollins suggested that debate performances would be important for Bachmann in the next few weeks.

“Legitimately, it’s a Romney-Perry race,” Rollins said. “I think [Bachmann]’s the third candidate at this point in time, which is way different and better than we thought when we started this thing. She’s very much in this thing.”

In previous Republican debates, most of the field declined to make a case against then front-runner Romney. At this point, Romney and Bachmann can’t afford not to land any punches on Perry during the September 8 debate at the Reagan library.

Who will be the first to go after Perry? Will they focus on flaws in his record as Texas governor, his opposition to building a new fence on the Mexican border, or his support for Al Gore’s presidential campaign in 1988?

Any comments about the Republican presidential race in Iowa or nationally are welcome in this thread.

I get a chuckle every time I run across one of those web ads for Representative Thad McCotter. Red background with Mao Tse-tung graphic and slogan like, “Thad McCotter will stand up to the Chinese.” “Thad McCotter understands the Chinese threat.” Sorry, McCotter: you’re not going to follow Joe Biden’s path from “foreign policy wise man” to vice-presidential candidate.

UPDATE: A super-PAC supporting Bachmann, Keep Conservatives United, is on the air in South Carolina with this attack ad on Perry:

My transcript:

Male voice-over w/southern accent: Rick Perry says he’s one tough hombre on spending.

Clip of Perry speaking from a podium at the 2011 Republican Leadership Conference: “Number one is don’t spend all the money.” [sound of cash register ringing]

Voice-over: But what’s his record? Rick Perry doubled spending in a decade, [newspaper clip from Star-Telegram, with headline “Texas spending kept rising for years with Perry as governor”; pull quote from the Texas comptroller says “Over a decade Perry doubled spending”]

And this year Perry is spending more money than the state takes in, [cash register noise in background, newspaper clip features quote from comptroller, “Perry spending more than state takes in”]

covering his deficits with record borrowing. [Wall Street Journal headline from August 23, 2011: “Texas Sells State Record $9.8 billion in Short-Term Notes”]

And he’s supposed to be the tea party guy? [photo of Perry in cowboy hat, next to words “Tea Party Guy?” on screen]

There is an honest conservative, [Screen shows Mother Jones story from July 19, 2011. There’s a photo of Michele Bachmann, and the headline reads “Poll: Michele Bachmann–Yes, That’s Right–Claims Top Spot in GOP Field”]

and she’s not Rick Perry. [on left side of screen, photo of Bachmann smiling with American flag in background; on right side, photo of Perry wearing cowboy hat]

Paid for and authorized by Keep Conservatives United. [www.keepconservativesunited.com on screen]