You are right Phil Kidd, and whoever the library employee was should be disciplined for saying that to you. Besides the stupidity and ugliness of the remark, the employee was "on the clock", and it is outrageous to think that the individual thought they had the liberty to make that kind of comment to a patron. 
Intolerance and lockstep thinking coming from the "left" is just as corrosive and damaging to democracy as it is coming from the "right".