Don't expect much gun-control legislation anytime soon. Historically, it takes at least a few years after a massacre or assassination to get sensible laws passed. Certainly, there’ll be no progress on gun control while the House is in Republican hands.
But the next time the Democrats have both houses of Congress and the White House, expect real gun control to move for the first time in years.Meyer (an assoc. prof. at the very conservative George Mason U.) makes the argument "[o]ne of the key components of the NRA’s power has been the support of moderate and conservative Democrats. Even when the Democrats controlled Congress, there were more than enough pro-gun Democrats to vote with most Republicans and bat down any efforts at gun control."
Meyer argues that key component is gone.