If it's possible to wear out your welcome in politics, you can wear out your welcome mat, too.
Sarah Palin's protracted flirtations with a presidential run took her to Iowa this weekend. She attacked President Obama, took at shot at what she called the "permanent political class," and even outlined a tax plan she said was designed to revive American hiring.
She even did what every politician does -- profess not to care about what polls say -- with a Palin twist:
"Polls -- nah. They're for strippers and cross-country skiers," she said.
Palin is running in Iowa -- in a half-marathon today.
But Palin did not declare a candidacy, of course. She didn't rule it out, either -- but that part has less potential relevance as the Republican field evolves without her.
In a GOP field for 2012 that's been defined as much by who's not running as by who is, Palin has been the question mark who's cast the largest shadow. With her celebrity status, fired-up base of supporters, and near-universal name recognition, she's remains a political force.
Yet her potential to compete seriously for the Republican nomination -- never a given to begin with -- diminishes with every passing week.
In a Fox News poll taken last week, a startling 72 percent of Republicans said they don't want Palin to run for president. Among self-described conservatives, 71 percent say they don't want a Palin candidacy in 2012; that figure is 62 percent among those who consider themselves tea partiers.
With bus tours and book signings and well-timed, well-placed speeches, Palin has sought to stoke political flames around a potential candidacy for the entirety of this campaign season.
The show continues Monday in New Hampshire, at another tea party rally, this one in a state where 23 percent of Republican voters said in a recent poll they wouldn't support Palin "under any circumstances."
But Labor Day brings the traditional start of a more intense period of campaigning -- a period that Palin is playing in from the sidelines.
The leading Republican candidates will be in South Carolina Monday, at a candidates' forum organized in part by Sen. Jim DeMint, R-S.C. DeMint said on ABC's "This Week" that he's satisfied with the current field -- sending something of a message to those who aren't current candidates.
"I'm excited about our field. I think the more people find out about the Republican candidates, the more strengths they see," he said. "I think that's why a lot of people have hesitated to jump in."
Among those who haven't hesitated, the race is heating up, entering a period when the Republicans will start to draw distinctions among themselves, and not just between themselves and President Obama.
Former Gov. Mitt Romney, R-Mass., has said he will outline his jobs plan Tuesday, as he confronts a race reordered by the latest entrant into the field, Gov. Rick Perry of Texas. Perry gets his first crack on a debate stage Wednesday, at the Reagan Presidential Library in California.
Even among non-candidates, the buzz around a possible candidacy by Gov. Chris Christie of New Jersey is eclipsing the questions swirling around Palin.
Palin herself may not be bothered by how things are developing. She's seemed to enjoy toying with what she calls the "lamestream media" -- a media that, of course, still rushes to cover her speeches and Facebook postings, even as she doesn't run for president.
But if she's still mulling a run, the race for her looks different than it did at the start. Other candidates -- Perry and Rep. Michele Bachmann, R-Minn., primarily -- are making aggressive plays for voters who might have supported Palin, given the opportunity to do so.
Volunteers and activists in the early-voting states want an answer from Palin, and frustration over lack of a definitive word plays out in commitments to other candidates.
If she does run, Palin has promised to be "unconventional," and few doubt that she'll run her own way. But at some point, conventional things like signing up activists and donors, even qualifying for state primary ballots, begin to matter in a significant way.
The question around Palin, as she remains non-committal, becomes less about will-she-or-won't-she. It will be whether the race that's developed around her ultimately cares.