Hispanidad is not a race, it's an ethnicity....
All peoples from Hispanic cultures (ie. countries that have a strong Spanish influence and/or history) are hispanic.
Being Hispanic is irrelevant to a particular race, being Hispanic is more on the lines of ethnicity rather than race.
Here are some example of ethnic classifications in the United States, which proves that Dominicans would be accepted as Hispanic whether they are white, black, or mulatto:
Definition of Hispanic:
http://en.wikipedia.org/wiki/Hispanic#Racial_Diversity
"In 1990, the Census Bureau added two race categories: American Indian, Eskimo, or Aleut and Asian or Pacific Islander. In addition, the Bureau added two ethnic origin codes: Non-Hispanic origin or Latino and Hispanic or Latino origin. (This site shortens these categories to simply Non-Hispanic origin or Hispanic origin.) Thus, a person could be reported for any combination of race and ethnic origin, e.g., Black (Non- Hispanic origin) or Black (Hispanic origin)"
Source:
http://tx.rand.org/stats/popdemo/popraceage.more.html
Overview of Race and Hispanic Origin in the Census 2000
http://www.census.gov/prod/2001pubs/cenbr01-1.pdf
In this PDF document about the Labor Force, notice the ethnic categories. Again, which one will the average Dominican falls under? It's hispanic.
http://www.bls.gov/opub/ooq/2001/winter/art06.pdf
Definition of what or who is a Hispanic:
HISPANIC
These are a set of ancestry codes for persons of Hispanic origin. They overlap to a great degree with the ancestry variables. Persons of Hispanic origin may be born anywhere, including the U.S., and may have any U.S. citizenship status. Separate Hispanic origin codes are assigned to Spain and to each of the nations of Spanish America. In some cases, a range of codes are assigned for each nation, with the separate codes corresponding to different ways of phrasing responses to the question. Note that there are no Hispanic codes for persons of Brazilian or Portuguese origin; these persons can be identified using the ancestry variables.
Source:
http://www.ats.ucla.edu/stat/census/census1980_1990/RACETHN.htm
This website is geared towards Hispanics, Dominicans included:
http://www.hispaniconline.com/
-NALs