The chairman of the Senate Judiciary Committee said Friday he won't support Attorney General nominee Michael Mukasey, potentially derailing his confirmation over complaints that he hasn't taken a full enough stand against torture.

"No American should need a classified briefing to determine whether waterboarding is torture," said U.S. Sen. Patrick J. Leahy, D-Vt.. He planned an afternoon news conference to make the announcement in Burlington.

Sliding support among the panel's Democrats makes it less likely the full Senate will vote to send Mukasey to a Justice Department that has been leaderless for weeks. Four Democrats on Leahy's panel, which will decide Tuesday whether to approve Mukasey's confirmation, have already said they will not support him.