I think he meant culture and politics has been similar since the time of ancient Rome, maybe thinking the United States existed that long ago.
It did not.
To play the ultimate Devil’s Advocate, the Romans did leave a lasting cultural impact on Brittain. So in a way we have a cultural bloodline that is distantly connected to Rome.
The American system is a direct descendant of Enlightenment Classicism, which includes a respect for the Classical Republics. Athens, Rome, Thebes, etc.
American federal government and arguably as a result liberalism is quite literally an imitation and attempt at modernization of the Roman Republic, which is, among other things, why we adopted the eagle as a national symbol and have a fasces in the House of Representatives.