What happened in New York's 23rd district is just the beginning. A recent Rasmussen poll of likely voters found that if the so-called "conservative base"—the people behind the national "tea party" movement—were to split from the Republican Party, they might actually win more votes than the more moderate remainder of the party. In a generic three-way race 36% said they would vote for the Democrat, 23% would vote for the Tea Party candidate, and only 18% would vote for the Republican.
The Tea Party candidate was actually the top choice among independent voters, with almost three times as many independents saying the would vote for the Tea Party candidate than would vote for the Republican. And a separate Rasmussen track poll found that 73% of Republican voters think their leaders are out touch with the party's base. It's no wonder Sarah Palin might consider running for president as an independent in 2012.
These results need to be taken with a certain grain of salt. As Christopher Beam points out, Rasmussen polls often seem skewed toward conservative results, in part because the "likely voters" who respond to automated telephone polls tend to be older and more passionate about political issues. And fully 22% of respondents said they were undecided. As Beam argues, it's unlikely that a newly-founded Tea Party would actually beat the Republican Party. Third parties tend to sound and do better in theory than in practice. As Rasmussen puts it, "it is unlikely that a true third-party option would perform as well as the polling data indicates. The rules of the election process—written by Republicans and Democrats—provide substantial advantages for the two established major parties."
Nevertheless, if the poll results are even approximately right, it's reason for the tea-partiers to flex their muscle. Breaking with the Republican Party would probably be disastrous, at least in the short term, for both them and more moderate Republicans. But the tea-partiers have a lot of leverage, and can certainly make the case that they should play a strong role in shaping the party agenda. The problem is that even if they win some disaffected Republicans back to the party they will also certainly alienate more moderate Republican and swing voters. While the poll doesn't show how a Tea Party would do against the Democrats in a two-way election, it's a good bet that the Democrats would win.