Budget battle crosses into Medicare

>> reporter: i'm kelly o'donnell on capitol hill , where the house republicans' budget man called for dramatic cuts and changes.

>> we put the nation on the path to actually pay off our national debt .

>> reporter: 41-year-old wisconsin congressman paul ryan is going big. compared to the white house budget laid out in february, the republican plan over the next decade would cut government spending by $6 trillion, reduce the federal deficit by $4.4 trillion compared to the president's budget, according to the congressional budget office . both parties and the president's own bipartisan debt commission say the federal debt is a national emergency .

>> this is the most predictable economic crisis in our history. and what are we doing, playing politics?

>> reporter: the biggest flash-point is altering medicare , where health care costs have soared.

>> we propose that we support people more if they're low income, more as they get sick, and wealthy seniors don't get as much support.

>> reporter: for anyone 55 and older, no change. but when younger workers reach retirement, they would choose private health insurance like federal workers and get a government subsidy to help pay for it. and medicaid for the poor would be controlled by states. democrats call the republican plan too severe, saying it would hurt the most vulnerable.

>> no longer would medicare be a guarantee of health insurance coverage. instead, medicare would become little more than a discount card. this plan would literally be a death trap for some seniors.

>> reporter: on taxes republicans propose lowering the top tax rates for individuals and corporations to 25%. so this boils down to republicans got a big spotlight today to argue their case. but many of the specific ideas face real resistance politically. still, republicans say this was a starting point. brian?

>> kelly o'donnell on the hill. and chuck todd at the white house before that starting us off tonight. thanks to you both. one more note on politics. florida democratic congresswoman debra wasserman schultz , who we saw right toward the end of kelly 's reporting there, was named the new head of the democratic national committee today. and she will keep her day job in congress at the same time.