Rain and the Tea Party: Watery tea HOW influential is the Tea Party? The anti-tax protests that erupted in 2009 have long since been hijacked by every right-wing group with the wit to add the words "Tea Party" to its letterhead. But new research suggests that the people whom left-wing pundits once dismissed as "teabaggers" made a big difference in the mid-term elections of 2010, when Republicans recaptured the House of Representatives. That victory had many causes, from economic gloom to disillusion with Barack Obama. But four economists have found an ingenious way to measure the effect of the Tea Party. They looked at the more than 500 tax-day protests of April 15th 2009. They also collected rainfall data for that day. When it rained, attendance at rallies halved - tricorne hats make poor umbrellas. Dry rallies created momentum: afterwards, 13% more locals became Tea-Party organisers than in places where it rained, and the rallies a year later were twice as large. Such enthusiasm translated into a 7% rise in the Republican vote in 2010, compared with wet areas. If the Tea Party merely expressed voters" frustrations rather than inflaming them, one would expect no difference between wet and dry districts. The authors conclude that protests can indeed shape policy. Watery tea may be weak, but the strong stuff makes lawmakers sit up and take notice.