Definition: In this task, you will be presented with a passage and have to answer a question based on your understanding of the events inferred from the passage. Try to find the best answer that is most likely to fill in "_". Note that the URLs in the text have been replaced with [Link].
Input: (CNN) -- The sun was barely up when New York Mayor Michael Bloomberg used the Colorado massacre to scold President Obama and Mitt Romney for ignoring the gun issue. "This is a real problem. No matter where you stand on the Second Amendment, no matter where you stand on guns, we have a right to hear from both of them concretely," Bloomberg argued. Bloomberg challenges Obama, Romney to take action on guns He has a point -- gun policy is a back burner debate these days, largely because Democrats who had pushed for tighter gun laws concluded it's bad politics.Bloomberg: "We have a right to hear" from Obama and Romney on gunsEx-congressional aide: "For many Democrats, it's smart politics" not to join gun debateThe Democratic-led Senate hasn't voted on any gun legislation in three yearsWhite House race could be decided in states where NRA has influence over swing voters 
 Question:That hasn't kept the _ from mobilizing members against him.

NRA