WASHINGTON, April 25 - Ridiculing the Bush administration's port security plans, Democrats on Capitol Hill on Tuesday called for the overseas inspection of every shipping container headed to the United States.

The Democrats, who are energized by the embarrassment caused to President Bush by the failed plan by a Dubai company to take over the management of six American port terminals, see the debate on ports as a central element of their election year push to make domestic security an issue that they can call their own.

At a news conference on Tuesday, a group of Democrats announced plans to offer amendments to measures in the House and Senate to require the comprehensive container inspections at all ports overseas.

"Ronald Reagan used to say, 'Trust but verify,' " said Representative Edward J. Markey, Democrat of Massachusetts.