This is a simple matter. As simple as it comes.
Any politician who cannot vote in favor of gun control in some form needs to be fired from his job.
I'm not asking for a blanket ban. Background checks, limits on bullet purchases, smaller magazine sizes, assault weapons bans, anything. Anything.
But if you are in elected office, and you can't do that after all this, you need to go. You aren't just a bad politician -- you are an accessory to mass murder.