As political movements go, the tea party phenomenon has become difficult to pin down. Yet whether one can define what tea partiers stand for and predict how they will vote, there is no denying the effect they are having on this year's elections.

The movement began in mid-2009 during the debate over health care reform. Those who rose up in opposition fancied themselves as the protectors of liberty, like the Bostonians who dressed as Indians and dumped British tea in the harbor.

As the groundswell grew, so did the feeling that something important was taking shape, one with clear ideals: Smaller government, lower taxes and an adherence to the original aims of the U.S. Constitution.

We applauded this rise of citizen activism to replace the apathy that too often has left ballots unfilled after Election Day and played into the hands of incumbent politicians and their powerful benefactors. When people get involved in their government, government will respond.

But in recent months, something seems to have watered down the tea.

What began as a concept based on ideology has changed as other issues and advocates have invited themselves to the party. Where the tea partiers originally rejected the rigid social agenda of mainstream conservatives, now those issues have found their way onto its banners and platforms. While the original goal was to "throw the bums out" and start fresh with less-entrenched lifelong pols, a number of incumbents have managed to glom onto the tea scene in an effort to become part of the "in" crowd.

And a few on the far extremes of both politics and sanity cast aspersions on the whole group by spewing the kind of racial intolerance more often heard at a skinhead rally than a legitimate political gathering.

The result is that it's now hard to know where the tea party folks stand. Where they once appeared to be hoisting the "Don't Tread On Me" banner of libertarianism between the GOP and Democratic battle lines, they now have adopted mainstream views that are hard to differentiate from most Republicans. The movement started as an expression of the electorate's anger, but unfocused anger alone isn't going to get anything accomplished.

That may explain why respondents to a Mason-Dixon Research poll commissioned by the Georgia Newspaper Partnership offered mixed response to a question about the tea party. While 48 percent of those polled said they favored its agenda (78 percent of Republicans, 48 percent of independents), only 16 percent consider themselves actual members (just 28 percent of Republicans).

Much of this ambivalence can be laid at the feet of Sarah Palin, erstwhile governor of Alaska and John McCain's high-octane, high-maintenance running mate from 2008. She has crashed the party in a big way, flying around the country and parachuting in to add her "you betchas" to the campaigns of numerous candidates

Palin has sought to adopt the tea party's ideal as her own and remake herself as its queen. She backs what she calls "mama grizzlies" — most of them women, all so-called mavericks opposing establishment GOP candidates — with the idea of turning the "good ol' boy" network on its ear and doing some of that good reformin' in Washington.

She's had mixed success, some of her candidates rising to victory on her well-cut coattails, others falling short. But Palin's backing may have mixed effect because it doesn't seem to be based on anything but personality. She seems more focused on charisma and a good background story over experience, policy ideas and substance.

For example, one of Palin's drop-in endorsements came in the Georgia gubernatorial primary, where she backed former Secretary of State Karen Handel. Her support was credited for lifting Handel into first place in the July 20 vote and into a runoff with Nathan Deal. But she lost that contest narrowly, despite another Palin visit that cost her more than $100 grand.

Handel had been blasted by her fellow Republicans in the primary because she was seen as being too chummy with gays, soft on same-sex marriage and not conservative enough on social issues. Apparently that didn't matter to Palin, whose other protégés fit the more traditional GOP views on both fiscal and social topics.

Karl Rove and other GOP leaders have expressed concern that many Palin-supported gate-crashers are underqualified and doomed to failure, their ascent likely to hurt the party's chances in November. As a result, other candidates seem less inclined to seek the tea people's backing.

It's clear that the tea party has an effect, but it remains hard to measure. Like the Ross Perot insurgency of the 1990s, it may fade quickly if it lacks the ideals to set it apart from the same old two-party script.

And at some point, if the "outsiders" are elected, they will have to become insiders and work with mainstream Republicans and Democrats to get anything done. If not, they will remain marginalized and ineffective, a tiny minority of gadflies in a sea of whales. Yet if they go along to get along, it could turn them into the kind of mushy compromisers tea partiers will target for defeat. That's the Catch-22 for any who take office.

We can "throw the bums out," sure, but what "bums" are we throwing in? Can this uprising put an imprint on our politics beyond one election? Or is the concept of remaking our politics, however attractive, doomed by its own ill-defined core?

The idea of a grass-roots political crusade to shake up our well-established party leaders is refreshing and welcome. But it will only attract widespread support and rise above the status quo of inaction if it stands for something clear and profound that connects with voters.

Otherwise, it's just a bunch of grizzly bears carrying signs and tossing tea around.