A few of the definitions that I've heard implied, if not stated explicitly:

1. The idylic life that we lived during the Eisenhower years.

2. Firmly believing that we have more human rights, and better living conditions, than absolutely anyone else on earth, and looking down on every other country because of it.

3. Appreciating the fact that we live with a credible amount of personal freedom and opportunity, and happy to see that extend to others around us.

All of which may just be rephrasing good observations that have already been made here.
                            Dean