Rep. Michele Bachmann (R-Minn.) had a good summer, moving from second-tier Republican presidential candidate to viable frontrunner and winner of the much-watched Ames Straw Poll in Iowa. But according to a new poll from Public Policy Polling (PPP), Bachmann is stuck in third place in must-win Iowa, behind new frontrunner Rick Perry (22 percent) and Mitt Romney (19 percent). Bachmann, who polled at 18 percent, also saw the number of Iowans who view her unfavorably skyrocket — from 16 percent in June to 35 percent now. "The day of her win in Ames may be remembered as the peak of her campaign," says PPP's Tom Jensen. Is this really the beginning of the end for the Bachmann campaign?

Yes. Bachmann's done: Like fellow flash-in-the-pan candidates Herman Cain, Donald Trump, and Newt Gingrich, "Bachmann's moment has come and gone," say Evan McMorris-Santoro and Kyle Leighton at Talking Points Memo. And it's not just PPP's survey: Other polls and anecdotal evidence shows her rapidly losing supporters to Perry, who is starting to blunt his "sharper policy edges" while Bachmann builds a "reputation as an extremist who says silly things."

"Peaked? Polling shows Bachmann support withering..."

Hold on. Bachmann is still better off than she used to be: It's true that PPP's numbers aren't great for Bachmann, says Katrina Trinko at National Review. But it's a Democratic polling firm, and the 5.5-point margin of error actually puts her in an essential tie with Perry and Romney. More importantly, while the Ames Straw Poll arguably should have pushed her above 18 percent in Iowa, she has significantly "increased her support since June," when PPP registered her at 11 percent.

"Perry leads in Iowa"

Plus, it's simply too early to write Bachmann off: Third place isn't good enough for a candidate who absolutely needs to win the Iowa caucuses, says Tim Murphy at Mother Jones. But "don't count Bachmann out just yet." It's "very, very early" in the race, and Perry is "riding the wave that comes with a high-profile announcement tour." His numbers will fall. But even if they don't drop much, caucuses aren't "straight-up popularity contests; they're time-consuming affairs that rely heavily on organization." In that respect, Perry may actually be too late to match Bachmann's critical Iowa ground game.

"Poll: Bachmann peaked at Ames, birthers not going away"