UPDATE: Barack Obama responded personally to Sarah Palin's speech, saying, "You're hearing an awful lot about me, most of which is not true. What you're not hearing is a lot about you." Watch the whole thing.
Barack Obama's camp issued a statement in response to Sarah Palin's speech:
"The speech that Governor Palin gave was well delivered, but it was written by George Bush's speechwriter and sounds exactly like the same divisive, partisan attacks we've heard from George Bush for the last eight years. If Governor Palin and John McCain want to define 'change' as voting with George Bush 90% of the time, that's their choice, but we don't think the American people are ready to take a 10% chance on change."
On Obama's campaign plane, top strategist David Axelrod responded:
"There wasn't one thing that she said about Obama or what he's proposing that is true. She tried to attack Senator Obama by saying he had no significant legislative achievements. Maybe that's what she was told."
On Wednesday, Republicans sought to define Obama as untested and inexperienced, making light of his past work as a community organizer in Chicago.
"For everyday people, ... that seems like real work," said Axelrod.
Ultimately, Axelrod said, the Republicans squandered an opportunity to promote their candidate. He also questioned the emphasis on McCain's years as a prisoner of war, saying the Arizona senator's history already was well known.
"They're shedding an awfully lot of heat but no light," he said. "It almost defies the laws of physics."
As for Palin's claim to be an outsider, Axelrod said that given her pointed criticism of Obama, "for someone who makes the point that she's not from Washington, she looked very much like she would fit in very well there."
Obama campaign manager David Plouffe also sent an email to supporters:
I wasn't planning on sending you something tonight. But if you saw what I saw from the Republican convention, you know that it demands a response.
I saw John McCain's attack squad of negative, cynical politicians. They lied about Barack Obama and Joe Biden, and they attacked you for being a part of this campaign.
But worst of all -- and this deserves to be noted -- they insulted the very idea that ordinary people have a role to play in our political process.
You know that despite what John McCain and his attack squad say, everyday people have the power to build something extraordinary when we come together. Make a donation of $5 or more right now to remind them.
Both Rudy Giuliani and Sarah Palin specifically mocked Barack's experience as a community organizer on the South Side of Chicago more than two decades ago, where he worked with people who had lost jobs and been left behind when the local steel plants closed.
Let's clarify something for them right now.
Community organizing is how ordinary people respond to out-of-touch politicians and their failed policies.
And it's no surprise that, after eight years of George Bush, millions of people have found that by coming together in their local communities they can change the course of history. That promise is what our campaign has been about from the beginning.
Throughout our history, ordinary people have made good on America's promise by organizing for change from the bottom up. Community organizing is the foundation of the civil rights movement, the women's suffrage movement, labor rights, and the 40-hour workweek. And it's happening today in church basements and community centers and living rooms across America.
Meanwhile, we still haven't gotten a single idea during the entire Republican convention about the economy and how to lift a middle class so harmed by the Bush-McCain policies.
It's now clear that John McCain's campaign has decided that desperate lies and personal attacks -- on Barack Obama and on you -- are the only way they can earn a third term for the Bush policies that McCain has supported more than 90 percent of the time.
The email asks contributors to help fight back by making a donation.
Senate Majority Leader Harry Reid, who Palin claimed "can't stand up to John McCain," fired back, with a spokesman deeming her speech "shrill and sarcastic":
"Anyone who knows Senator Reid knows he never backs down when he's fighting for what's right and that he always stands up to John McCain when he is wrong," Jim Manley, Reid's press secretary, told CNN. "Shrill and sarcastic political attacks may fire up the Republican base, but they don't change the fact that a McCain-Palin administration would mean four more years of failed Bush-Cheney policies."
On NBC's Today, Joe Biden called Palin's performance "one heck of a political speech" and "Karl Rove stuff" that avoided issues or policy proposals "to dig us out of the hole the Bush administration has dug us into." But it showed, he said, that Palin would be a "formidable" opponent and "very skillful debater." Watch: