Texas Attorney General Ken Paxton is defying Donald Trump's likely preference of Sen. John Cornyn (R-TX) by refusing to drop out of the Senate runoff race, a move that could derail the president's efforts to resolve the GOP's costly and divisive primary battle, reports NBC's Melanie Zanona."No, I'm staying in this race. I owe it to the people of Texas," Paxton declared in a phone interview with Real America's Voice. "I've spent a year of my life campaigning against John Cornyn, because John has...