Four weeks ago, a handful of frustrated but determined tech leaders in San Antonio met to talk about how they could galvanize their community into greater cohesion and political action. In retrospect, the departure of Uber and Lyft proved to be a rallying cry. Tuesday evening marked the official launch party of TechBloc (@SATechBloc), and the turnout exceeded all expectations as the movement caught fire on social media.“Six grew to 60 and now look at you!” said Lew Moorman, a tech investor and former longtime president of Rackspace, as he spoke to crowd of 600 people that filled Southerleigh Fine Food & Brewery and spilled on to the patio and plaza. “This happened in only four weeks.” Only the fire code kept more people from pushing inside to hear Moorman and David Heard, chief marketing officer for SecureLogix.