This quote is from the Wikipedia article about McCarthy.
Ultimately, McCarthy's tactics and his inability to substantiate his claims led him to be censured by the United States Senate. The term "McCarthyism," coined in 1950 in reference to McCarthy's practices, was soon applied to similar anti-communist pursuits. Today the term is used more generally to describe demagogic, reckless, and unsubstantiated accusations, as well as public attacks on the character or patriotism of political opponents.
It seems to me that this word "racist" is being used in exactly the way that McCarthy used the word "communist". Of course some of those people many years ago probably really were Communists, just as some of the people who are being labeled as Racist today probably really are. But the Senate eventually condemned his witch hunt, and I'm hoping that the current ready accusation of Racism will also be condemned with enough force and power behind it to actually stop this constant labeling.
I guess it's from having lived through the McCarthy era, as well as the Civil Rights Movement, that gives me a different perspective on the use of this word than many younger people have today.