Washington (AFP) – A mass shooting that left 19 schoolchildren and two teachers dead in the deeply pro-gun state of Texas on Tuesday increased pressure on US politicians to take action over the ubiquity of firearms — but also brought the grim expectation of little or no change. It was the eighth mass shooting this year, according to the Everytown gun control group, and came 10 days after another 18-year-old murdered 10 African Americans at a supermarket in New York. But nearly 10 years after a man slaughtered 20 children and six others in an attack on the Sandy Hook elementary school in Newto…