Hispanic is not a race. Most Hispanics are white.
As used in modern discussions about demographics, the term “white” is given to mean non-Hispanic whites. When Hispanics were a tiny demographic that wasn’t the case. Now that they are poised to eventually be the largest demographic group in America in a few decades, you don’t really have to say “non-Hispanic white” when discussing race. If you mention “white” and you mention “Hispanic”, then most people have the intelligence to understand that “white” means “non-Hispanic white”.
The “non-Hispanic” is silent.
Oh, and as regards casual conversation, which I realize is not TECHNICALLY precise, Hispanics are often called or considered to be “brown” so as to distinguish them against non-Hispanic whites. Even though there is no such thing as a “brown race”.
Like I said, it is “understood” rather than “explicit”. 99 percent of people will understand what you mean when you are talking about issues of race or demographics and casually allude to “whites” vs. “Hispanics”.
It is not that complicated.
The Hispanic Caucus, LaRaza, MEChA, LULAC and the myriad of other groups have little trouble distinguishing who is Hispanic. Race or not