Here are the laws relating to cousins marrying in the US. Guess that argument sort of falls by the wayside huh?
Alabama and Alaska allow first cousins to marry with no proscriptions. Arizona allows it if they are beyond child bearing age.
•California: First cousins, yes.
•Colorado: First cousins, yes.
•Connecticut: First cousins, yes.
•Delaware: No
•District of Columbia: First cousins, yes.
•Florida: First cousins, yes
•Georgia: First cousins, yes.
•Hawaii: First cousins, yes.
•Idaho: No
•Illinois: First cousins, yes, only if they are over a certain age or cannot bear children.
•Indiana: First cousins once removed, yes, only if they are over a certain age or cannot bear children.
•Iowa: No
•Kansas: Half cousins, yes.
•Kentucky: No
•Louisiana: Marriage between first cousins is not allowed.
•Maine: First cousins, yes, only if they are over a certain age or cannot bear children, or if they get genetic counseling.
•Maryland: First cousins, yes.
•Massachusetts: First cousins, yes.
•Michigan: No
•Minnesota: No, unless aboriginal culture of the couple permits cousin marriages.
•Mississippi: Adopted cousins, yes.
•Nebraska: Half cousins, yes.
•Nevada: Half cousins, yes.
•New Hampshire: No
•New Jersey: First cousins, yes.
•New Mexico: First cousins, yes.
•New York: First cousins, yes.
•North Carolina: First cousins, yes. Double first cousins are not allowed to get married.
(wow SM doesn't even know the laws of his own state.)
•North Dakota: No
•Ohio: No
•Oklahoma: Half cousins, yes.
•Oregon: Adopted cousins, yes.
•Pennsylvania: No
•Rhode Island: First cousins, yes.
•South Carolina: First cousins, yes.
•South Dakota: No
•Tennessee: First cousins, yes.
•Texas: No.
•Utah: First cousins, yes, only if they are over a certain age or cannot bear children.
•Vermont: First cousins, yes.
•Virginia: First cousins, yes.
•Washington: No
•West Virginia: Adopted cousins, yes.
•Wisconsin: First cousins once removed, yes, only if they are over a certain age or cannot bear children.
•Wyoming: No