Sources close to former President Trump say he has a plan for keeping Congress from ever again forcing him into “disgraceful” and “ridiculous” spending situations. If he returns to the White House, Trump will seek to resurrect authority that Congress stripped from the presidency almost a half century ago. What President Nixon squandered, his campaign promises, Trump will restore, namely the impoundment power. “A lot of you,” the former president told a New Hampshire crowd Thursday, “don't know what that is.” Indeed, few now remember it. Impoundment, if restored, would allow a president, in theory, to simply refuse to spend...