Donald Trump has outraged members of his own party by saying that the race of federal judges could determine whether they're qualified to hear certain cases. But even John McCain has finally endorsed him, and there won't be a contest at this year's Republican convention.
The Democrats may be in for something different, with Bernie Sanders promising that the convention will be "contested" — regardless of whether he wins or loses tomorrow in California. That raises the question of what that might look like. Ron Elving, senior editor and political correspondent at NPR's Washington Desk, revisits contested conventions in the past.