AdvertisementKoch Brothers, Behind Tea Party Wave, Face Democrats' Rising Tide In 2018January 30, 2018Tim MakfacebookEmailTea Party activists hold a rally on Capitol Hill in 2010. That grassroots movement, with backing from the Koch political network, helped Republicans win back the House in the 2010 midterms. In 2018, the Koch network is on defense against Democratic gains. (Getty Images)