How does this occur between a Hispanic and a white person?

Because most hispanics are part white so the white genes dominate.

Many of my family members have had babies with whites and they all come out looking white.

You wouldn't even think they're mixed.

Depends what kind of Hispanic looking your talking about. Most Hispanics are mixed people, most are mixed of White-Indian or White-Black or White-Indian-Black.

However, since most Hispanics are mixed and mixed comes in Brown skinned, many people think that all Hispanics are Brown skinned. Am Tanned skinned myself and I am mixed of White-Indian-Black and I look more White-Indian looking than Black but my cousins look like full White Europeans. It is weird actually. Also, most Hispanics are part or have White blood. The Whites genes will come first than the Indian or African traits than the person has. If the person Indian or African traits come than, the Indian or African traits will appear more on that person than their White roots. Am Tri-racial Hispanic. I am mixed of White-Indian-Black, however, you won't noticed that am part of Black, you will called me a Indian because of my skinned color or half white and half indian because of my eyes, but I am tri-racial and my White and Indian ancestry made me look more European-Indian than African.

I am a mixed Hispanic and most Hispanics are mixed people.

I speak Spanish as my first language but language has nothing to do with race.

Am Puerto Rican and being mixed with three races, it is not for all of the Hispanics though. Most Mexicans are mixed of White or Indian so, no African will come out of that.

Because hispanic isn't a race. And there is no "hispanic" look. Hispanics come in all races and mixes.

I know it's sad. I have full Mexican cousins/relatives who look pure white.