There have been several chapters in the still-extremely-early 2012 presidential race. There was the time that Newt Gingrich's smarts and policy chops was going to shake up the contest. That ended. There was the time Herman Cain's business acumen and tea party ties were going to be a real factor in the race. That didn't work out. Then, of course, there was Donald Trump. Remember him?

Now, it appears, Michele Bachmann's moment has come and gone.

When Bachmann jumped in the presidential fight, more than a few pundits predicted she had a real shot at the nomination thanks to their view of a Republican Party more likely to pull another Christine O'Donnell next year than pick a real threat to President Obama.

Those pundits may still prove prescient, but the numbers show it's becoming less and less likely. The reason? Texas Gov. Rick Perry. His entrance into the race — and his brand of tea party friendly politics and executive experience — seems to be Bachmann's problem.

Polls have shown a sharp decline for Bachmann, despite being the frontrunner in the Ames Straw Poll and eventually winning it. And the one major reason is the entrance of Perry. Nationally, Bachmann's presence is being displaced by Perry, who jumped ahead of the field in the latest Rasmussen survey, the first choice of nearly a third of respondents, with Bachmann only registering 13 percent.

Even Iowa, absolutely essential to her campaign, is turning sour. In a We Ask America poll conducted on August 16, Perry registered 29 percent, with Bachmann in second with 17 percent. In a PPP poll that will be released later today, Bachmann comes in third in a GOP Primary trial heat, her unfavorability numbers having jumped nearly twenty points from a previous PPP survey in June.

There may be more to it than polling. On the ground in South Carolina last week, more than one unaffiliated professional Republican said that Bachmann's crowds were still of the more extreme activist variety, leaving her with a narrow slice of the primary electorate. Bachmann's pitching a relatively extreme message on the trail as well, despite the Ames win that raised her profile beyond the tea party where her popularity is never in doubt.

Perry, on the other hand, is actively rounding over his sharper policy edges, allowing him to still exist in the tea party sphere while leveraging his office for maximum electability.

Bachmann, on the other hand, is still talking about shutting down the Department of Education and standing by her refusal to vote for an increase in the debt ceiling under any circumstances (not to mention her social views, which she mentions often.) That definitely makes some in the GOP very happy, but it also makes her a tougher sell to Republicans hoping for a candidate with a reasonable shot at the White House in 2012.

Try as she might — and impressive as her campaign has been so far — Bachmann has not been able to shake off her reputation as an extremist who says silly things. When she was the fresh and new alternative to Mitt Romney, those problems seemed to be less important. But now that she's running alongside two former governors with big national bases, the issues she came into the campaign with seem to be pushing her back onto the sidelines.

Republished with permission from TalkingPointsMemo.com. Authored by Evan McMorris-Santoro and Kyle Leighton. Photo via AP. TPM provides breaking news, investigative reporting and smart analysis of politics.