They are organizing early, they say, to prevent what happened last year, when several Tea Party candidates split the vote in Republican Senate primaries, allowing the most establishment of the candidates to win with less than 40 percent.

The meeting in Sharpsville was hardly the exception. Just three months after the midterm elections, Tea Party organizers are preparing to challenge some of the longest-serving Republican incumbents in 2012.

In Maine, there is already one candidate running on a Tea Party platform against Senator Olympia J. Snowe. Supporters there are seeking others to run, declaring that they, too, will back the person they view as the strongest candidate to avoid splitting their vote. In Utah, the same people who ousted Senator Robert F. Bennett at the state?s Republican convention last spring are now looking at a challenge to Senator Orrin G. Hatch.

The early moves suggest that the pattern of the last elections, in which primaries were more fiercely contested than the general election in several states, may be repeated.

They also show how much the Tea Party has changed the definition of who qualifies as a conservative. While Ms. Snowe is widely considered a moderate Republican, Mr. Hatch is not. Mr. Lugar, similarly, defines himself as a conservative. He argues that he has consistently won praise from small-business groups, supported a balanced budget amendment and pushed for a reduction in farm subsidies and the closing of agricultural extension offices as part of an effort to reduce unnecessary spending ? all initiatives that fall under the smaller government rubric of the Tea Party.

?Some of this is a feeling that it?s time for new blood,? said Brendan Steinhauser, an organizer with FreedomWorks, a national group that has worked with Tea Party groups on several primary challenges.

Mr. Lugar said at a breakfast with reporters this month that he believed that many Tea Party supporters were motivated by anger ?about how things have turned out for them.? They want to express themselves, but their complaints often boil down to nothing more specific, he said, than ?we want this or that stopped, or there is spending, big government.?

?These are all, we would say, sort of large cliché titles,? he said, ?but they are not able to articulate all the specifics.?

The advocates in Indiana, which national Tea Party groups say has the most organized of the primary efforts, point to Mr. Lugar?s push for the New Start nuclear treaty, which the Senate approved in December; his sponsorship of the Dream Act, which would grant a path to citizenship for limited groups of illegal immigrants; and his votes for President Obama?s picks for the Supreme Court, Justices Sonia Sotomayor and Elena Kagan.

?The senator would call it bipartisanship, but we think you?re siding with the other side,? said Greg Fettig, a Tea Party supporter in Indiana.

Another, Mark Holwager, said, ?He may have been a conservative at one time, but he definitely leans to the left now.?

The coalition of Tea Party groups, calling itself Hoosiers for a Conservative Senate, plans to hold a caucus in June where the 70-odd groups involved will choose a candidate to run against Mr. Lugar in the primary next May. In the meantime, the group has designated a coordinator for each of the state?s Congressional districts to begin a campaign to educate voters about what Tea Party supporters call Mr. Lugar?s liberal record.

The group has also had discussions with several national groups that played a role in primaries last year where establishment candidates or Republican incumbents lost to Tea Party challenges, including FreedomWorks, the Tea Party Express and the Club for Growth.

Those behind Tea Party challenges say they learned their lesson about splitting the vote from several primary contests last year, including the Senate races in Illinois and Indiana and Congressional races in Virginia, where a flood of Tea Party candidates resulted in a moderate or establishment candidate winning.

But so far there are few declared candidates. In Utah, some Tea Party supporters say they would back a run by Representative Jason Chaffetz, who won his Congressional seat in 2008 after challenging an incumbent Republican, Chris Cannon, in the primary. That race became a kind of trial run for Tea Party primaries, with many of the same people who worked on Mr. Chaffetz?s campaign working to unseat Mr. Bennett last year.

Still, there is some division. The Tea Party Express, a national group started by longtime Republican consultants, recently announced that it would not back a challenge to Mr. Hatch, calling him ?as good as it gets? for Republicans. The Club for Growth, which has poured money into other Republican primary challenges, issued a statement disagreeing.

Utah is a reliably Republican state, so whoever wins the primary is almost assured to win the general election.