WASHINGTON (AP) — Mitt Romney on Friday unveiled a plan to fundamentally re-shape Medicare, tackling one of the 2012 presidential contest's most delicate issues before a skeptical crowd of tea party activists.

To cut costs, the Republican presidential hopeful and former Massachusetts governor would introduce vouchers, or "premium supports," to future recipients of the popular health insurance program for the elderly. Romney addressed the lightning-rod issue during a fiscal policy speech before an afternoon gathering of conservative activists at the Washington Convention Center, where the tea party-allied group Americans for Prosperity is holding a two-day event.

Romney has struggled to win tea party support, and his plan is a nod of sorts to those who want to slash behemoth government programs. In other areas he may not go as far as some conservative activists would like, but Romney says he would cut federal spending by $500 billion in his first term as president.