they can't. the Embassy denied them non-immigrant visitor visas. We even had our congresswoman intervene. sucks for them.
I can visit there without a visa because I was lucky to be born in a country that is not total crap, only sort of crap.
side note: places that would be better to be born from a work/life balance, health and life expectancy point-of-view: Sweden, Norway, Finland, Denmark, France, Germany, the Netherlands, Belgium, Luxembourg, Monaco, Japan, Switzerland, or Canada. But the U.S. isn't that bad. None of those places have Michigan Football, but Canada is close enough to get broadcasts, I think.