WASHINGTON (AP) — Digging in for a bruising struggle, Republicans on Congress' powerful deficit-fighting "supercommittee" targeted Social Security and government health care spending Tuesday while Democrats pressed for higher tax revenue as part of any deal to reduce red ink by at least $1.2 trillion over the next decade.

There were no ultimatums from either side, and there was even a fleeting suggestion that tax reform might eventually clear the way for the bipartisan agreement that both sides say they want.

Yet with the Census Bureau reporting national poverty at a 28-year high and partisan struggles flaring elsewhere in Congress, the events underscored the challenge the 12-member panel faces as it gropes for a deal that can clear Congress and win President Barack Obama's signature by year's end.