Extremists have always used disinformation and fear-mongering to further their cause. But their rhetoric about immigration has stooped to new lows in recent months.Some of the lies are so outrageous it might be tempting to laugh. Haitian immigrants, for example, are not eating their neighbors’ pets in Springfield Ohio. And 107% of American jobs have not been taken by “illegal aliens,” as Trump claimed. (107 percent? How would that even work?)But the misinformation is no laughing matter. It’s ...