The Congressional Research Service (CRS) works for the United States Congress and supplies policy and legal analysis to members, regardless of party affiliation.
Anyway, the CRS compiled a Financial Aid for Students Guide, updated March 2009. A very thorough source: http://demint.senate.gov/public/index.cfm?FuseAction=Services.StudentAid
Now, here is where a little intuitive web searching can come into play. Your scholarship and internship guru decided to google Congressional Research Service. Of course, there were several opportunities for internships on their website.
Student Diversity Internship Program
One program I looked at had a deadline of July 31, 2009; one deadline had already passed; you will have to check the deadlines of the various programs.
Law Recruit Program
Presidential Management Fellows Program at CRS