I think that’s a phrase chosen to be intentionally provocative, not necessarily anyone’s actual indications.
It’s hard to argue that in many ways, the US has been great. Is still great as a matter of fact. I mean, the nation has done a lot of great things and represents a lot of great stuff, even today. So it’s not incorrect or insensitive or anything to say that America was and is great.
But… it’s not inaccurate to say that while the nation was and is great, it is not as great as it could have been, or still can be, either.
And that’s where I think that Cuomo, et al were getting at, but intentionally playing off of the MAGA nonsense to point out how we don’t want to go backward/curl inward and go back to the greatness of the past, which was not that great when compared to what we can be if we go forward. The unfortunate part is that the phrasing implies that the nation was not great in the past in an absolute sense, instead of a relative sense.
19 June 2003. The US’s prior low point was 09 August 1974 with the resignation of President Nixon. That, coupled with the US army being defeated in Vietnam, and the US was in the doldrums. However, it recovered starting with the 1976 Bicentennial celebration which was a marketing success for patriotism. The personal computer boom and the economic success of the 1980’s followed a few years later. The US had some minor military successes in that period and then the Berlin Wall fell and the Soviet Union broke up. The major success of the first Gulf War soon followed, and economically the Internet boom had kicked off and was flourishing. It would have been pretty hard to argue against US greatness in 2000.
Then, the 11 September 2001 attacks happened. They were a sharp, emotionally devastating shock, but not a blow to US greatness. If anything, the rest of the world rallied around the US and supported the response in Afghanistan. But then came the second Gulf War with the military invasion starting on 20 June 2003. GW Bush could have claimed success up to that point for forcing Iraq to allow in the weapons inspectors, and could have forced a permanent overwatch presence. Instead, he gambled on, and underfunded, an Iraqi liberation. That largely failed, and did so at a great monetary cost. The US then took another big hit, this time economic, with the 2008 financial crisis. The US has been in recovery mode ever since. It’s had some bright areas such as the post-Internet/smart phone boom and the killing of Osama bin Laden. However, it’s also had an incredible amount of small-mindedness and divisiveness. Now, the US is polarised between the left and the right with both sides contemptuous of the other. When a large majority of Americans believe that half of America (the other half) is terrible, no outsiders are going to view it as great.