ThatPurpleGuy said:
Just google "Inbreeding" or "incest" and I am sure there will be plenty about health risks. Of course I am not an expert but this has always been my understanding and that of everyone I know.
I think you have it the wrong way around. It would probably take several generations of inbreeding to reverse the mess created in the first place. Just get with someone other than your family, its not that hard.
"A 1998 review found 1-4% increased morbidity for offsprings of first cousin marriages compared to offsprings of unrelated parents. A 1994 review found 4.4% increased mortality for offspring of first cousins. After controlling for several sociodemographic factors, infant mortality for offspring of first cousins had odds ratios of 1.36, 1.28, and 1.32 for the neonatal, postneonatal, and infant period. There has been little research on how inbreeding affects common adult disorder although some preliminary evidence support effects on many such disorders including cardiovascular diseases and common cancers. Many previously not identified genetic disorders have first been recognized in highly endogamous communities and the mutation causing the disease may be unique to such communities.[20] A review of 48 studies of children born to cousins found that most of the children were healthy, with birth defects affecting 4% of births for consanguineous couples compared to 2% for the general population"
http://en.wikipedia.org/wiki/Inbreeding#Humans
4% genetic defects (if we take the highest-rating studie) compared to 2% in "ordinary couples". Twice as likely, yet not a "huge" chance.
So yes, it is a health-risk, but apparently, not a big enough one to be concrned with (atleast where I live).
And honestly, it's more likely that the children will be "genetically defect" if you marry someone that has a genetic disease, than if you marry your first cousin, and we don't ban that, now do we?
Still, I'm more interested in the public opinion than arguing if it should be legal or not.