Restricting democracy: Republicans trying to prevent college-age students from voting

I don't really see how the whole idea of this is constitutional or rational. Considering Republicans are trying to restrict US citizen's right to vote, a right which the constitution guarantees us at the age of 18, I don't understand how some of these insane bills even get passed. Also since there is little to no voter fraud, I really cannot fathom how people are drinking the Republican kool-aid and thinking this is a good idea.

God dam people. We should just go back to segregated schools with morning prayer where only God-fearing white-property-owning-males can vote. Just like the good old days, right?