It is very conceivable that the Lefties are trying to steer the Nazi/KKK nutbags to the tea parties so that the Lefties can paint them as massive KKK rallies. Both the Nazis and the Lefties benefit in their own ways, while us conservatives lose.
No, this is SOP. They see a recruiting opportunity. They simply have to be rejected. If you search you'll find a number of threads a few years back about infiltrating FR. Nothing particularly new, but there is a political price if their support is embraced.