Democrats are wrapping up the fourth and final day of their National Convention in the western U.S. city of Denver, Colorado, with a much anticipated speech by their nominee, Senator Barack Obama.   Obama made a surprise appearance at the convention Wednesday after his vice presidential candidate, Senator Joseph Biden gave his acceptance speech.  VOA Correspondent Cindy Saine has the story from Denver.

Sen. Barack Obama looks at venue at Invesco Field at Mile High, 27 Aug 2008, where he will accept Democratic nomination for president

Senator Barack Obama surprised his running mate and many others when he showed up on stage one day ahead of schedule.  The 47-year-old explained why Democrats are moving the entire mammoth convention for the last day from an indoor venue in Denver to a nearby outdoor sports stadium.

"So we want to open up this convention to make sure that everybody who wants to come can join in the party and join in the effort to take America back," Obama said.

Thursday's events will feature elements of a rock concert and a big party, including performances by Stevie Wonder, Sheryl Crow and will.i.am.  There will also be a tribute to the slain civil-rights leader Dr. Martin Luther King, and former Vice President Al Gore will speak.

But the main focus of the evening will be on Barack Obama's speech.  Political analyst Larry Sabato says presumptive Republican nominee Senator John McCain has put Obama in a difficult position with his negative television ads depicting the Democrat as a media celebrity like many others.  The ads flash images of Britney Spears and Paris Hilton alongside Obama speaking to adoring crowds in Berlin.

"McCain has put Obama in a box," noted Sabato. "On the one hand Obama is expected to give one of the best speeches in American history, so expectations are enormously high.  There will be 75,000 people, an unprecedented number in attendance, cheering him on.  But because of the attacks on Obama as 'just another celebrity', if it looks too much like a rock concert, Obama could actually be penalized for doing well.  He could also be penalized if the speech does not meet the skyrocketing expectations for another Gettysburg address." [The famous speech delivered by President Abraham Lincoln during America's Civil War.]

Political analyst Stuart Rothenberg agrees that Obama does not have an easy task ahead of him as he reintroduces himself to the nation.

"Well he probably cannot do what he really would like to do, which is make people comfortable about him, about his foreign policy experience, about the direction of change that he wants to bring, and I think that will take time," Rothenberg said.  "What he realistically can do is impress people.  Remind them, those who do not know him, how articulate he is, how sharp is, what a great motivator he is, and generally get good reviews."

Sen. Barack Obama, (r), and Democratic VP candidate, Sen. Joe Biden at the Democratic National Convention in Denver, 27 Aug 2008

Wednesday was veteran Senator Joseph Biden's time in the spotlight, and he gave an emotional acceptance speech for the vice presidential nomination.  The Chairman of the Senate Foreign Relations committee said on several major foreign policy decisions, Senator Obama was right and his opponent Senator McCain was wrong.  He sought to link McCain to Bush administration policies.

"I have been on the ground in Georgia, Iraq, Pakistan, Afghanistan and I can tell you in no uncertain terms, this administration's policy has been an abysmal failure.  America cannot afford four more years of this failure," Biden said.

 Also speaking Wednesday, former U.S. President Bill Clinton repeated over and over that Senator Obama is ready to be president.  While supporting his wife, Senator Hillary Clinton in her quest for the candidacy, Mr. Clinton spent months on the campaign trail questioning Obama's qualifications.

Former President Bill Clinton addresses the crowd during the Democratic National Convention, 27 Aug 2008

"Barack Obama is ready to honor the oath to preserve, protect and defend the Constitution of the United States.  Barack Obama is ready to be president of the United States," Clinton said.

Voters are watching to see what kind of speech Obama gives, and then attention will shift back to the Republicans.  Senator McCain is expected to announce his vice presidential pick soon and the Republican National Convention begins next week in Minnesota.