The New York senator still has not said whether she will ask that her name be put in nomination to allow her backers what she has called a cathartic vote for her before throwing their support to her first-term Senate colleague from Illinois.
A new poll, meanwhile, showed Obama and McCain virtually tied.
The Pew Research Center survey of gave Obama three-point advantage at 46-43 percent.
The same poll showed Obama leading McCain by 8 percentage points in June, though by July his lead was 5 points, about the same as now. Since June, McCain has solidified his support among whites, men, Republicans, white evangelicals and whites who haven't completed college.
Obama has made few gains, but has retained his overwhelming advantage among blacks and leads by 13 points with women and 24 points among those under age 30. Seven in 10 who backed Clinton now support Obama - little progress for Obama since June. Growing numbers pick McCain over Obama as the candidate who is personally qualified, could handle a crisis and is willing to take a stand.
Obama retains his edge as the one with new ideas and connects with people.
A recent Associated Press-Ipsos poll showed 43 percent of registered voters were undecided about which candidate to support.
That includes 15 percent leaning toward Obama or backing him while saying they could change their minds, and 16 percent tentatively supporting McCain. Another 8 percent are undecided, and 4 percent weakly back third-party candidates Ralph Nader or Bob Barr.
That's a bit more than were uncommitted at this stage in 2004, when an AP-Ipsos poll showed 37 percent in the same category. In that race President George W. Bush, who is more familiar to the public than McCain, was seeking re-election.
On Tuesday, Obama and Republican opponent John McCain issued dueling statements about Russia's invasion of American-allied Georgia, a complex conflict that has opened a window on the differing diplomatic mindsets of the men vying to become the next U.S. president.
Wednesday morning, Bush said Secretary of State Condoleezza Rice was heading to Paris and onward to Tblisi, the Georgian capital. He also said the U.S. military had already begun sending humanitarian aid by sea and air.
"Russia must keep its word and act to end this crisis," Bush said in a statement he read in the White House Rose Garden.
McCain touts what he calls his overwhelming edge in experience in foreign affairs and security issues. He has been hitting the Kremlin hard for sending troops, armor and attack aircraft against the tiny Caucasus country, which gained independence after nearly two-centuries of Russian dominance with the collapse of the Soviet Union in 1991.
Obama, too, has been full-throated in condemning the Russian attack but has called for restraint on both sides. Initially, he did not entirely absolve Georgia of a role in provoking Moscow by trying late last week to forcibly impose central government authority on the breakaway South Ossetia region.
He has subsequently toughened his stance. Susan Rice, a top Obama foreign policy adviser, defended the call for restraint.
"It was not clear at that stage" what the actual conditions were and Obama wanted to react cautiously "rather than shooting from the hip."
Obama's "subsequent statements have been a reflection of events on the ground," Rice said.
Ossetians live on either side of the spine of the Caucasus Mountains that form the border between Russia and Georgia. The South Ossetians, whose land lies in Georgia, have gained Kremlin protection as they have sought fitfully since the early 1990s to join with North Ossetia, on the other side of the Russian border.
At a campaign stop in Pennsylvania, McCain told a cheering crowd that he had just spoken with Georgian President Mikhail Saakashvili, offering moral support and telling him: "Today, we are all Georgians."
The longtime senator had taken a tough stand against Moscow even before the invasion, calling for the Kremlin to be expelled from the Group of Eight, the organization of the world's richest nations known as the G-8. McCain says Russia has no place in the group given the increasingly authoritarian tendencies that have taken root under former President Vladimir Putin, who now has installed himself as prime minister.
Obama's most recent words on the crisis, a two-sentence statement issued Tuesday from his Hawaiian vacation retreat, declared, "It is past time for the Russian government to immediately sign and implement a cease-fire. Russia must halt its violation of Georgian airspace and withdraw its ground forces from Georgia, with international monitors to verify that these obligations are met."
On Monday, Obama told the Russians "There is no possible justification for these attacks." At the same time, however, he said "Georgia should refrain from using force in South Ossetia and Abkhazia, and a political settlement must be reached that addresses the status of these disputed regions." That was a clear acknowledgment that Georgia, too, needed to change course.
Abkhazia is a second region in northern Georgia that has broken away, also under Russian protection. The Kremlin has based what it calls "peacekeepers" in both regions as a deterrent to Georgian desires to bring them back under central government control.
---
On the Net:
McCain: http://www.johnmccain.com
Obama: http://www.barackobama.com
