If you choose to ignore numerous human rights abuses that started before independence and lasted until about 1965 then you probably do have model for a really great country, but you can't rewrite history and reality has to be accepted.
Slavery 1619-1865
Displacement of Native Americans 1600s-1800s
Jim Crow 1870s-1965
Asian immigrants expelled from California towns (1880s)
Lynching 1882-1964 (up until 1935 there were lynchings in the double digits)
Japanese Internment (1940s)
Legal citizens deported in Operation Wetback (1950s)
That is a terrible human rights record for a first world nation even if it is in the past. There is nothing wrong with acknowledging that the country is not perfect and has become better over the past few decades. Cuomo is not even going to come remotely close to losing over this and his presidential campaign probably won't go anywhere but that is because he hasn't been as liberal as some Democrats would like.
Jeez, this is why the term "liberal" got tarnished over the last 40 years. It's not even incorrect, but it is a strain of pessimism and lack of respect for the uniqueness of the American experience - the bad and the good - that turns off even moderates (and liberals like me).
Obama made the case for American exceptionalism better than anybody else in modern history.
From his convention speech in 2016:
Poll
