Shared from Zite 163 House Democrats – over 80% of the entire caucus – signed onto an open letter [PDF] Thursday addressed to Republican House Speaker John Boehner demanding that he allow "a vote on substantive legislation to address gun violence." The timing of the letter suggests that Democrats are prepared to make gun control in an issue in the 2014 midterm elections, despite evenly divided public opinion and staunch opposition from the powerful National Rifle Association (NRA). John Hames shared with you: Democratic House members demand gun control vote msnbc.com - Gun control, long a dormant issue in American politics, surged to the forefront of the Democratic agenda following December 2012's massacre at Sandy Hook Elementary School in Newtown, Connecticut. Yet in the fol...