> criticism of liberals is that they are unpatroitic and 'don't love America'
Being patriotic has nothing to do with being nationalistic. It's one thing to love your country, support it, etc... but it's another thing entirely to believe your country is so great, all others fail in comparison, everyone's out to get you (because you're so great), your nation must always be "top dog" and set all global policies, etc...
Being ultra-nationalistic could be paralleled with a phobia of sorts.
> lack of response by liberals and moderates in authority positions - why are they silent?
They aren't silent. The US Executive Branch is currently liberal (as is the State Department, and Secretary of Defense... all foreign policy makers), and certainly has aided the growing sense of extreme nationalism with all the anti-non-european-countries rhetoric. The general message often conveyed is, if you aren't part of North America or Europe, then you're out to get us.
This instead of saying "We may have our differences, but we have worked together in the past and achieved great things, and we can work together now to achieve great things."
> The more nationalistic parties, pushing nationalistic and nativistic (e.g., anti-immigrant) plicies, are always conservative: The Republicans in the U.S., the Tories and the right-wing extremists in the UK
This is extreme partyism, and just as wrong as extreme nationalism.
All parties are guilty. As are all ideologies. They just have different ways of showing it.