The Constitution also makes no mention of a language test for territories or properties that wish to become states . NEW : A pro - Santorum campaign buys $ 1 in ad space in Illinois . Santorum says that it should be illegal for Puerto Rico to become a state . Romney 's campaign responds with a statement saying he would not require that . Puerto Rico , next on the campaign trail , has a statehood referendum in November .
NEW : A pro - Santorum campaign buys $ 1 in ad space in Illinois . Santorum says that it should be illegal for Puerto Rico to become a state . Romney 's campaign responds with a statement saying he would not require that . Puerto Rico , next on the campaign trail , has a statehood referendum in November .