Actually, Republicans have repeatedly supported this measure. Sarah Palin championed it just last year for ALL Alaskans. Only now---only in a democratic bill---does she call it 'death panels'. http://thinkprogress.org/2009/08/13/palin-deathpanel-flipflop/
Republican Johnny Issacson (R-GA) was the one who added the amendment. Newt Gingrich just wrote an article 2 months ago calling for it, as it reduces costs to medicare by 30%.