Sen. John Kerry (search) hasn't gone away quietly. In his first major speech since conceding the presidential election, the Massachusetts Democrat took aim at President Bush's health care proposals on Thursday, saying they were irresponsible and won't meet the needs of children and low-income families who don't have health coverage.

Going head to head with Bush, who was unveiling his plan for computerized medical records at about the same time, Kerry criticized the administration's failure to negotiate drug prices or consider drug reimportation.

"That's how the president who promised to usher in a 'responsibility era' proposes to deal with a real health care crisis, even as he seeks to gin up a phony crisis in Social Security," said Kerry, in remarks prepared for delivery to the nonprofit consumer group Families USA (search). "It sounds like a cradle-to-grave irresponsibility plan to me."

Bush also has been promoting plans for health savings accounts, which Kerry opposes.

Republican National Committee spokesman Danny Diaz questioned Kerry's commitment to health care, saying he was "long on political attacks and short on credibility."

"Over the course of Senator Kerry's two decades in Congress, he has introduced virtually no health care legislation," said Diaz.

Kerry is pushing his own proposal, which would provide health care to all children through an expansion of the Medicaid (search) program. The federal government would absorb states' costs for children at or below poverty level, to encourage states to expand coverage to children in families that make less than about $47,000. It would cover children up to the age of 21.

The plan, said Kerry, fulfills one of his campaign commitments because "it's a promise we not only can afford to keep, but one we cannot afford to break."

While it's a legislative longshot in a Republican-controlled Senate struggling with a budget deficit, Kerry is vowing to push for hearings in the Finance Committee and force debate by trying to attach it to any bill he can.

The speech is the latest in a series of moves Kerry has made against the Bush White House. Last week, Kerry issued a public call for Defense Secretary Donald Rumsfeld's ouster, and he was one of two senators in the Foreign Relations Committee to vote against the nomination of Condoleezza Rice as secretary of state.