Science Policy Opportunities and Resources: 

Engaging Scientists & Engineers in Policy Coalition: http://science-engage.org/students.html

National Science Policy Network: http://scipolnetwork.org/

Journal of Science Policy & Governance: http://www.sciencepolicyjournal.org/

Union of Concerned Scientists: https://www.ucsusa.org/

More in-depth news coverage: 

Politico: http://www.politico.com/

Real Clear Politics: http://www.realclearpolitics.com/

Roll Call: http://www.rollcall.com/

The Hill: http://thehill.com/

National Journal: https://www.nationaljournal.com/

AAAS Budget Analysis: https://www.aaas.org/program/rd-budget-and-policy-program

Science Insider Blog: https://www.sciencemag.org/news/scienceinsider

Updates on current legislation:

Federal Register: https://www.federalregister.gov/

GovTrack: https://www.govtrack.us/congress/bills/

OpenCongress: https://www.opencongress.org/bill/pending

Senate Active Legislation: http://www.senate.gov/legislative/active_leg_page.htm

House Legislation and Votes: http://clerk.house.gov/legislative/legvotes.aspx

AIP FYI Science Policy News: http://www.aip.org/fyi

Interesting political analytics/Big Data:

FiscalNote: https://www.fiscalnote.com/

Quorum: https://www.quorum.us/