I would say that MOST liberals are NOT unpatriotic. However, there is absolutely no question that FAR MORE liberals are unpatriotic than conservatives or moderates. Also, liberals are far more likely to be disdainful of the very concept of patriotism.
Patriotism, when overt and audacious, can become ugly.
Not always, but sometimes. Maybe tyou remember that thread about the aussie woman in Florida who went to put out an aussie flag because all the neighbours had american flags and they wouldn't let her?
Liberals may be more likely to be unpatriotic, but conservatives are more likely to be jingoistic and audacious in patriotsm. Not every conservative, but more then the liberals.