Do Illegal Aliens Have Constitutional Rights? Courts Have Ruled They Do By Robert Longley, While illegal aliens do not enjoy all of the rights granted to citizens by the Constitution, specifically the rights to vote or possess firearms, these rights can also be denied to U.S. citizens convicted of felonies. In final analysis, the courts have ruled that, while they are within the borders of the United States, illegal aliens are granted the same fundamental, undeniable constitutional rights granted to all Americans. Illegal Aliens and Constitutional Rights – Do Illegal Aliens Have Constitutional Rights? That is the problem.