Tea Party activists helped Republicans win a landslide in the 2010 midterm elections, but they are already unhappy. Less than a year into the new Congress, they see a string of broken promises: the debt ceiling raised, insufficient spending cuts and politics being conducted behind closed doors. “The Republican leadership came in with promises that didn’t happen,” says Dawn Wildman, a national coordinator for the Tea Party Patriots. “They are doing backroom deals, not putting up bills online for seventy-two hours before voting on them, and not keeping other promises.”

Wildman is in regular contact with state and local Tea Party activists and she says they are displeased with their local Republican incumbents and open to backing primary challenges against them virtually everywhere. “There’s not one state saying ‘we just love our guys and want to keep them forever,’ ” says Wildman. “People are not willing to hold their nose to vote any more.”

Some Republicans, though, may be given a pass by the DC-based conservative organizations that often partner with the Tea Parties. For instance FreedomWorks, Dick Armey’s fiscally conservative group, takes a more pragmatic approach to politics. They intend to back right-wing challengers to senators in conservative states where the Republican primary essentially anoints the general election victor. But in Massachusetts, thus far, they are giving a pass to Republican Senator Scott Brown for his numerous heresies. “What you can get in Massachusetts is different than in Utah,” says Matt Kibbe, executive director of FreedomWorks. “I don’t see a better alternative to Scott Brown at this point.”

Wildman calls that view “incredibly short-sighted.” She says that Tea Party activists in Massachusetts “couldn’t wait to see Scott Brown gone. They’re more concerned with his RINO [Republican In Name Only] status than taking a Democratic seat. From outside we say that’s about the best you’re going to get, but on the inside there’s no compromise.”

Even so, there are plenty of states that grassroots Tea Partyers and national organizations like FreedomWorks will work together on, even if they haven’t yet found a candidate. Here are four Senate races to watch for Tea Party insurgencies.

Utah: “We’re going after Orrin Hatch,” says Kibbe. “We’re going to replace him with someone better.” Hatch, like his former Senate colleague from Utah Bob Bennett, has a fairly conservative, if establishment-friendly, track record. But Tea Party activists took over the Utah Republican convention in 2010 and booted Bennett off the primary ballot, thus ending his career. Hatch, like Bennett, voted for the TARP bailouts and showed a willingness, later abandoned, to work with Democrats on healthcare reform. “[Hatch’s] record looks like Senator Bennett’s,” says Kibbe. “Pro-spending, he supported virtually every bailout that’s been on the table, the individual mandate.”

But the thing that most sticks in the craw of Tea Party activists is that Hatch worked with Ted Kennedy to create the S-CHIP program, which gives health insurance to children from uninsured families that do not qualify for Medicaid.

Hatch has been on a charm offensive to win over Tea Party activists while eliminating prospective competition by raising vastly more funds than any prospectives opponent. Representative Jason Chaffetz, who was seen as Hatch’s strongest potential challenger, announced last week that he isn’t running. But Hatch is not in the clear yet. “We’re happy with some of the recent votes that he’s taken,” says David Kirkham, a Utah Tea Party organizer. “He stood up for Cut, Cap and Balance.” But, adds Kirkham, “he’s got some real stinkers of votes.” Hatch also, as conservative blogger Michele Malkin notes with disgust, co-sponsored a national service bill with Kennedy. Kirkham says the Utah Tea Party will be vetting candidates, looking for a challenger with private sector experience. Thanks to Utah’s unusual rules governing ballot access, Tea Party leaders think they can keep Hatch off the primary ballot, thus mooting his financial advantage. Any candidate who meets with Tea Party approval would surely be an uncompromising extreme conservative. Senator Mike Lee (R-UT), who unseated Bennett, voted against the debt ceiling deal, issuing a statement with Senator Rand Paul (R-KY) as to why.

Indiana: Just as Hatch’s relationship with Kennedy was a famous example of bipartisan friendship, Senator Dick Lugar (R-IN) mentored an Illinois freshman Democrat named Barack Obama. Lugar is fairly conservative, but he has made nuclear non-proliferation his legacy. “A lot of people are looking at Lugar,” says Kibbe.

Nominally the Tea Party movement is focused on economic and constitutional liberty. But as studies of its membership have shown, Tea Party activists are overwhelmingly conservative Republicans. The best predictors of Tea Party identification, in fact, are socially conservative views. So Lugar is being targeted mostly for a record of sensible, bipartisan work like nuclear non-proliferation treaties, that has nothing to do with taxing and spending.

James Bratten, state coordinator for the Indiana Tea Party Patriots, lists Lugar’s main apostasies as his role in the START treaty to reduce nuclear arms, supporting the nominations of Sonia Sotomayor and Elena Kagan to the Supreme Court, co-authorship of DREAM Act and voting for TARP. Bratten says conservative Indiana Republicans at the county level are lining up behind Richard Murdoch, the state treasurer. Replacing Lugar with a more doctrinaire conservative would be a major blow to bipartisanship, especially on foreign policy.

Florida: In 2010 the most high-profile Tea Party insurgency might have been Marco Rubio’s overwhelming destruction of Florida Governor Charlie Crist in the Republican Senate primary. Crist had been a rising GOP star as recently as 2008, when he was short-listed by Senator John McCain for the vice-presidential nomination. Then the party took its dramatic rightward turn and Crist’s moderate stances on some social and environmental issues made him persona non grata.

When Senator Mel Martinez stepped down, Crist had appointed his chief of staff, George LeMieux, to replace Martinez, safe in the assumption that LeMieux wouldn’t run for the seat in 2010 and Crist could. LeMieux served sixteen months, while Crist got trounced by Rubio. Now LeMieux is running for the nomination to challenge Senator Bill Nelson (D-FL), who is looking vulnerable. Tea Party icon Rep. Allen West (R-FL) has bowed out of the race, but Tea Party activists are coalescing around Adam Hasner, the former Florida House Majority Leader. So it’s a Rubio protégé (Rubio was Florida’s House Speaker) against a Crist protégé. Kibbe calls it a rerun of the 2010 race.

The candidates, naturally, are sparring over who is more conservative. LeMieux is touting his 92 percent rating from the American Conservative Union, while attacking Hasner for supporting a judicial bypass option in Florida’s parental notification abortion law and voting for earmarks. Hasner counters that LeMieux is guilty by virtue of his association with Crist. If either candidate unseats Nelson, Florida will have an awfully conservative senate delegation for a swing state.

Texas: With Senator Kay Bailey Hutchison retiring, Tea Partyers have a chance to replace her with one of their own. Democrats are virtually nonexistent in Texas statewide elections. While Hutchison is no moderate, she was defeated in the 2010 gubernatorial primary by Governor Rick Perry, who ran to her right and portrayed her as a member of the Washington establishment. Tea Partiyers are supporting Ted Cruz, the former Solicitor General of Texas. “There is a huge difference between Cruz and [Lieutenant Governor] David Dewhurst who is the establishment deep-pocketed candidate,” says Kibbe.

Cruz has won endorsements from right-wingers such as Rand Paul, Senator Pat Toomey (R-PA) and National Review’s Jay Nordlinger. Cruz has the perfect biography to excite any movement conservative. Half-Cuban, a debate champion at Princeton and a graduate of Harvard Law, he clerked for Judge Michael Luttig and Chief Justice William Rehnquist. (It’s funny how supposedly anti-elite conservatives suddenly remember how much they love a fancy educational pedigree when one of their own possesses it.) Nordlinger writes that “Ted should be a national conservative cause, the way Rubio was in Florida,” and goes on to fantastize about the “embarrassment of riches” in a future presidential primary between Rubio and Cruz. He’s getting ahead of himself, but if Cruz wins the primary he’s virtually certain to join Rubio in the Senate and gain national prominence.