Here's a Democracy Now! interview with a Haitian-American novelist Edwidge Danticat on Dominican Republic's "ethnic purging"
http://www.democracynow.org/2015/6/17/the_dominican_republics_ethnic_purging_edwidge
Also, the Dominican government has made it exceedingly difficult over the years for migrants and children of migrants to prove their nationalization. There is very small percentage of those that have been stripped of their right to nationality that have been able to successfully obtain the level of documentation being asked for by the D.R. government.
Here is a good overview of the issue from the Open Society for Justice Initiative and the Center for Justice and International Law produced in 2012.
Any appeal to legality and procedure becomes irrelevant when the laws and procedures are proven to be unjust and unfair.
It's analogous to defending Jim Crow or Nazi policies by saying "Well, it's the law" or "This is just standard procedure".