A tool like this in the hands of Tweet-meister and fact-twister and prevaricator Donald Trump is a mind boggler that must leave Joseph Goebbels drooling jealously in his grave.Beginning at 2:18 p.m. Eastern time Wednesday [today], Americans across the country will be interrupted by an urgent notification on their cellphones.“Presidential Alert,” the message will read. “THIS IS A TEST of the National Wireless Emergency Alert System. No action is needed.”...Wednesday’s [today's] test of the Wireless Emergency Alerts system will mark the first time that emergency management officials will have used the nationwide alerting capabilities reserved for the office of the president.Unlike other types of emergency alerts, the presidential alert is designed to let the White House inform the entire country almost instantly of grave public emergencies, such as a terrorist attack or an invasion, according to the Federal Emergency Management Agency. And while Americans can choose not to receive weather and AMBER alerts, they cannot opt out of presidential ones.Despite its name, Wednesday’s [today's] presidential alert will not be issued by President Trump directly. But in general, the process calls for the president — or his representative — to authorize FEMA to send an alert on the White House’s behalf.