Can you name the most contentious issue in American politics? Here's a hint. It's being fought at the federal, state and local levels. And it doesn't go away. The struggle is persistent, ongoing, unending. Here is a second hint. The issue is not gay marriage, or gun control, or police brutality and or immigration. Those issues are either settled, largely settled, isolated or completely out of the control of local and state governments. Here is a third hint. The issue divides Republicans and Democrats, conservatives and liberals. But it is especially divisive among Democrats and among people who call themselves...