Think American Greatness depend on who you ask. But on a more political historical academic point of view. You could say America was great when it the dominant empire. Today we are witnessing american decline in some areas, but in many areas there has been a lot of progress and in many areas America is still number one. But America great again is a catchphrase with vague meaning where people can put there own meaning.

On the one hand, it means a time when America was Christian and white, people specially older one would feel this when you compare 50-60s TV and movies with todays TV and movies. I mean look at Modern Family, Brooklyn nine nine, where Homosexuality is not a great taboo, where not everyone is white, but multicultural and the 50 there were no homosexuals, no blacks, no sex, well there is a different America in that sense, so some people will think of great america is white america, some in a conscious way other people may feel it more on an unconscious sublime way, where they don't like the shows they don't know why or they won't say is because you see too many blacks, or gays.

The other area of american dominance is economy, now you buy things made in china, clothes in Vietnam, cars made in Germany, Japan are much better, electronic appliances made in China, but brands Japanese, Korean, mobile phones made in Sweden, well hardly anything is made in USA, but there was a time, specially in the 50 when American products and industry were the only things you saw at the shops. The reality is that during those years Europe and Asia were recovering from WW 2 and not fully industrialized, so during that time felt America was great because there was no other country that could compete. But nowdays is not that America is not great is we live in a multipolar world, that is many countries now have better economies and have more influence and say in the world and you got the rise of China. So people felt there was a time were America dominated simply because China was not yet fully developed.

On the other hand for some is the feeling that America was great when people just worked hard and knew their place on society and there was not much noise, this is of course a time when minorities, gays, blacks, Jews, Latinos had fewer rights and were not visible, while now everybody makes noise if their rights are stepped on, and everybody is equal which makes for some white folks America a more unwelcome place or less great.

Republifucks have ruined any glimmer of a just and moral society.

I'm not American but I'm assuming it meant your Constitution, freedom including freedom to speech, rights to property as in private ownership of properties, which is kind of lost today, you are not allowed to freedom of speech in fear of being labelled racist or bigot, hate crime, you don't have ownership to things that are now owned by the government and if you do own a business the government tells you who you should employ