One of the favorite techniques of anti-Mormons is to falsely say that the Lamanites were cursed with dark skin. They falsely say that Latter-day Saints believe that there is something inherently wrong with someone because he has dark skin. By the dictionary definition of racism, this idea is certainly racist. The Lord commanded the Nephites not to intermarry with them, for if they did they would partake of the curse. The dark skin given to the Lamanites was simply a physical characteristic to distinguish the Lamanites and Nephites and to keep them from intermarrying.
Skin color has no moral significance one way or the other.
For the same reason that Latter-day Saints today are counseled not to date or marry nonmembers of the Church. Latter-day Saints who are married to nonmembers do not enjoy full Church participation, especially temple marriage. Furthermore, their children are far less likely to be faithful members of the Church. Now let's discuss the concept of racism as it applies to the Lamanites and Nephites through generations of time. No, actually there were times when specific Lamanite individuals and entire groups of Lamanite people were pronounced just as righteous and favored of God as most Nephites.