Nationalism - synonym: patriotism
Yes, nothing wrong with being a nationalist advocating for nationalism. Our founding fathers were, and so are Americans that love this country.
For the Nazis, their form of ‘nationalism’ had a definite racial spin..... so NOW, to be proud of your country is anathema
The people who hate US nationalism are the same people who do NOT know their history AND without knowing how or why, would support another tyrant who would hand them a twisted and deformed form of ‘nationalism’ they COULD swallow whole -like bunch of Nazis