Story Map (an app) has created interesting interactive interpretations of census data. This one is Comparing Metro and Micro Area Population Change between 2002-2003 and 2012-2013
The library subscribes to a variety of polling data, including Gallup Brain. But on Gallup's own site, the Presidential Job Approval Center, where users can track the President's approval rating on a daily basis, as well as comparing approval ratings of different presidents.
TaxVox is the Tax Policy Center blog. The Tax Policy Center is jointly published by Urban Institute and Brookings Institution.
Interested in online political communication? Scholars Anders Olof Larsson and Jakob Svensson summarize some of the current scholarship in order to identify opportunities for new scholarship in Politicians online – Identifying current research opportunities. First Monday, Apr. 2014.