It is these 21st century anxieties--anxieties about changes from outside America that seem beyond average Americans' control--that represent the Republicans' best shot at unhorsing Obama now.

现在，正是21世纪的这些担忧——关于外界的变化超出一般美国人的控制的担忧——成为共和党想让奥巴马落马的最紧要一枪。