First, go to the website for Council on Foreign Relations summary of the U.S. Immigration Debate and watch the video. Read the policy stances for Clinton and Trump.
Write about any aspect of Immigration Reform as it relates to one or both of these candidates.
Some possible options:
The Congressional Research Service (CRS) is a division of the Library of Congress that conducts research for the members of Congress as part of the legislative process. The CRS produces public domain reports on major policy issues, many of which are updated regularly. Here are some sources for obtaining CRS reports that may be useful for your paper.