I'm just addressing this generally but I've heard such things explained as along the same lines as "authority figures" (teachers for instance) having aggravating circumstance additions to sentencing. The logic (whether one agrees with it or not) is that public government officials, by merely being one, invite all manner of ire. I have to agree to some extent that being a government official is essentially setting oneself up to be a hate magnet. It's literally impossible, no matter your stance, not to have haters. So the POV becomes "Yeah yeah, hate all you want, hang/burn us in effigy, etc but any actual attacks have to get hammered hard as a clear line of demarcation or else it would just become commonplace.".