In the final hours of the second day of their convention in Boston, Democratic Party delegates have heard a stirring speech by a rising star in the party, and one by a former Democratic presidential contender.

Barack Obama, a 42-year-old African-American running for a seat in the U.S. Senate from Illinois, drew thunderous cheers with a speech combining impassioned calls for social justice in America and appeals to patriotism.

Mr. Obama said Senator John Kerry and his vice presidential choice, John Edwards, would, if elected, help middle class Americans.

He drew applause with his comments about hope in America and this call for social and racial equality. "John Kerry believes in America. And he knows that it's enough for some of us to prosper," he said. "For alongside individualism, there is another ingredient in the American saga. A belief that we're all connected as one people. If there is a child on the south side of Chicago who can't read, that matters to me even if it is not my child. If there is a senior citizen somewhere who can't pay for their prescription drugs, having to choose between medicine and the rent, that makes my life poorer, even if it's not my grandparent."

Mr. Obama also addressed the question of civil liberties under sharply strengthened homeland security laws put into force at the urging of the Bush administration, since the September 11, 2001 terrorist attacks. He asserted they have had a serious negative impact on the rights of minorities in America:

"If there is an Arab-American family being rounded up without benefit of an attorney, or due process, that threatens my civil liberties," he said.

Also addressing the convention, in the final hours of Tuesday, was former Democratic governor Howard Dean.

With his populist appeal, and strong criticism of the Bush administration on the economy and Iraq, Mr. Dean started as a favorite in the race for the Democratic presidential nomination only to fade quickly.

He told delegates a Kerry administration would restore U.S. credibility damaged by the war in Iraq.

"I'm voting for John Kerry and John Edwards because I want a president and a vice president as good and as strong as the American people. I'm voting for John Kerry and John Edwards because I want to see an America that is restored as the moral leader of the world," he said.

The convention enters its third day on Wednesday, highlighted by an address by Senator Kerry's vice presidential choice, Senator John Edwards of North Carolina.