Views on immigration reform are, in the first place, an ideological one.
Republicans think it is necessary to reduce the flow of immigrants in the country to avoid the loss of jobs of American citizens and to protect the nation from violence, including terrorism. This is a more conservative view, stimulated by the nationalism preached by the president.
The Democrats believe a less conservative immigration policy is important to spur the country's diversity. In this view, they mainly defend the legalization of the "dreamers", who are young and adult who were illegally brought to the United States as children, which makes them have identification with American values and culture. It is, therefore, a more liberal vision connected with the ethnic cultural formation of the USA.