As Democrats send presidential candidate Barack Obama off on his quest for the White House, the Republicans and their candidate, John McCain, are preparing for their national nominating convention, which begins Monday in Minneapolis-St. Paul, Minnesota. The Democrats made Barack Obama the focus of their convention this past week in Denver, and not surprisingly, the Republicans plan to do the same at their convention next week.

After all the convention speeches and political attacks, balloon drops and celebrity guests, the presidential election will still boil down to a simple choice - Democrat Barack Obama or Republican John McCain.

Political expert Stuart Rothenberg has been watching the Democrats hold their convention in Denver this week and has been looking ahead to the general election campaign, which begins in earnest after the Republican Convention.

"I do think the election continues to be about Barack Obama.The desire for change in the country is strong, and if Senator Obama can convince most Americans, the majority of Americans, that he will be a seasoned, sensible, trustworthy leader, I think they are going to take a chance with him. So far, he hasn't closed the deal."

Even in Denver, Republicans did all they could to cast doubt about Obama's political experience, his ability to lead the country and his readiness to be commander-in-chief.

Former New York City Mayor Rudy Giuliani lost out to John McCain in the Republican primaries this year, but Giuliani is now going after Obama as one of McCain's main surrogate campaigners.

"And I think Senator McCain would keep us on offense against terrorism, and therefore protect us, and I think Senator Obama would put us back on defense and that that would be certainly not as safe a situation for this country. Senator Obama's lack of knowledge about foreign policy is a serious concern.

Democrats are well aware of the concerns that Obama is simply too inexperienced, especially in the areas of foreign policy and national security.

Former President Bill Clinton reminded Democrats this week that this year's Republican attacks on Obama have a familiar ring to them.

"We prevailed in a hard campaign in which the Republicans said I was too young and too inexperienced to be commander in chief. Sound familiar? It did not work in 1992 because we were on the right side of history, and it will not work in 2008 because Barack Obama is on the right side of history!"

University of Virginia analyst Larry Sabato says the Democrats will also try to capitalize on Obama's early opposition to the war in Iraq.

"What the Democrats have been saying is that experience did not keep us out of an unpopular war and that judgment is better than experience. So they are stressing different parts of Obama's biography."

But McCain supporters are just as adamant that Obama's plan to withdraw most U.S. combat troops from Iraq within 16 months is reckless and jeopardizes the hard-won improvements in security inside Iraq.

Expert Stuart Rothenberg looks for a full week of attacks on Obama at the Republican convention in Minneapolis-St. Paul.

"But the McCain folks have been very aggressive in changing that, in putting the onus on Obama, and I think they will have to continue to be aggressive. Because the bottom line is that, although this race is close, and John McCain could win, Barack Obama has a slight advantage. And so, McCain has to continue to keep the heat on Obama."

Most experts agree the economy will be the major issue in the election this year, and, at the moment, they give Obama and the Democrats an edge in that area.

Recent polls show Obama and McCain in a virtual dead heat in the race for the White House, with less than 10 weeks to go until Election Day on November 4.