WASHINGTON (AP) — The House took up a stringent GOP budget plan Wednesday that blends big cuts to safety-net programs for the poor with a plan to dramatically overhaul Medicare, kicking off a politically-charged, election-year debate over trillion-dollar deficits and what to do about them.

The debate quickly split along partisan lines, with Republicans shunning tax increases on the wealthy called for by President Barack Obama, while Democrats resisted curbs on federal health care spending and further cuts to domestic programs. An alternative based on Obama's 2010 deficit commission promised to bring at least a glimmer of bipartisanship to the floor but was expected to fall victim Wednesday night to GOP opposition to tax hikes and Democratic resistance to further cuts to domestic programs.

The main focus, though, is on the budget-slashing GOP plan by Budget Committee Chairman Paul Ryan, R-Wis., which would quickly bring the deficit to heel but only through unprecedented cuts to programs for the poor like food stamps, Medicaid, college aid and housing subsidies. The Republican budget also reprises a controversial Medicare plan that would switch the program — for those under 55 today — from the traditional framework in which the government pays doctor and hospital bills to a voucher-like approach in which the government subsidizes purchases of health insurance.