By Debra J. Saunders WASHINGTON I start with a prediction: Big media will not look into would-be veep Tim Walz with the intensity they reserved for digging up dirt on JD Vance, after Donald Trump named the Ohio senator his running mate. There will be no stories about leaked texts the now-Democratic running mate sent to someone he once considered a friend. There will be no stories about fellow Democrats urging Kamala Harris to renege on her choic…