Weld's endorsement comes a day after former Bush Press Secretary Scott McClellan and the former Governor of Minnesota Arne Carlson, also a Republican, announced their support - separately - of Obama's candidacy.
"We need a president who will lead based on our common values and Sen. Obama demonstrates an ability to unite and inspire. Throughout this campaign I've watched his steady leadership through trying times and I'm confident he is the best candidate to move our country forward," he said.
As for McClellan, his preference for Obama was made public through a clip CNN distributed promoting a new TV program the network will debut tomorrow.
Appearing on "D.L. Hughley Breaks the News," McClellan said his vote is all about "change."
"From the very beginning I have said I am going to support the candidate that has the best chance for changing the way Washington works and getting things done and I will be voting for Barack Obama," he said to cheers and applause.
McClellan's decision isn't that much of a surprise. His book "What Happened: Inside the Bush White House and Washington's Culture of Deception" showed McClellan's distaste with the partisan ways of Washington, DC -- not to mention W.
Not quick to embrace
McClellan's endorsement has received mixed emotions around the blogosphere.
A visitor on the uber-blog site Gawker says thanks but no thanks.
I'm sorry, why would Obama WANT anyone from the Bush Administration, save Colin Powell, to endorse him? Isn't Scott McClellan reviled by Democrats and Republicans alike. Oh well. At least McCain has got Bush endorsing him. You really can't beat that.
Colin Powell is one thing, Scotty Boy...I don't think we'll see Obama embracing his endorsement so readily.
It was coming
Over at Talking Points Memo, lfchesterfield says it was inevitable.
"I guess it's like the broken clock thing: hang around long enough and eventually you'll agree with McClellan on something," the blog post reads.
On the right
Those on the right side of blogland aren't any more embracing. One writer over at HotAir has an interesting idea for a new McCain slogan.
Powell, Ken Adelman, now [McClellan]. McCain should run an ad saying, “If I’m George Bush, why are his cronies all voting for Barack Obama?”
With 11 days to go and Obama's polls strengthening, the McCain team just might take them up on this idea.