By Victor Davis Hanson, Wayne and Marcia Buske, Imprimis - First, we are blurring the line between mere residents and citizens. We have between 45-50 million non-native-born residents in the U.S. today — the largest absolute number we’ve ever had. There’s no legal problem with the 30 million of them who have green cards or have acquired citizenship — although even 30 million is a challenge for the American melting pot to assimilate and integrate… But we also have, according to a recent Yale and MIT study, about 20 million people who are here illegally. In regard to them, the classical ingredients of American citizenship — the right to leave or enter the country as one pleases, for example, or to vote in elections, or to reside here as long as one pleases — are being blurred.