Tea party threat again hangs over Republicans" efforts to retake Senate Many of the upstarts are considered long shots, and some are in states that are so deeply conservative that even a gadfly Republican would be likely to win in the general election. But a similar situation has tripped up Republicans in the past two elections, costing them seemingly winnable seats in states such as Nevada, Missouri and Indiana. Moreover, in a year in which the electoral map and President Obama's sagging poll numbers provide Republicans their best opportunity to win back the Senate in a decade, GOP veterans are increasingly frustrated by the amount of time, energy and cash that will be spent trying to deal with internal feuds. "They're really undermining everything we're trying to do here," Sen. Orrin G. Hatch (R-Utah), who stands to chair the powerful Finance Committee if Republicans win the majority, said of the independent groups that are providing financial and other support for the challengers. The path for conservative victories is through defeating Democrats, Hatch said. You can't do it by destroying sitting [GOP] senators. Conservative activists, however, say their goal is to remake the Republican Party from the outside, focusing their efforts particularly on red-leaning states where the incumbent is insufficiently strident in opposing Obama and Democrats. "All we want to do is pass a fiscally conservative agenda through the Senate," said Barney Keller, spokesman for the Club for Growth, which is the best-funded conservative outlet and is backing the challenger to Sen. Thad Cochran (R-Miss.), who was first elected in 1978. Several of the insurgents seized on a modest two-year bipartisan budget deal announced Tuesday evening, saying they opposed it because it raises spending too much. Aside from just challenging incumbents, groups such as the Club for Growth also hope they can push sitting senators further to the right. By helping defeat Sen. Robert F. Bennett (R-Utah) in 2010, for instance, the Club for Growth says it scared other GOP incumbents. "We got Orrin Hatch to vote a pro-growth agenda for two years," Keller said. Republicans need to pick up six seats to win the majority, while Democrats are defending 21 seats, including seven key Senate battlegrounds in places where Obama lost in 2012. That margin would be much smaller if not for a series of GOP candidates who emerged from ideological primaries in 2010 and 2012 as tea party heroes, only to blunder through the general election and lose winnable races.