Democratic presidential hopeful Barack Obama's campaign on Friday kicked off a new phase in its battle for the White House, declaring it would be more aggressive in combatting "lies" from opponents and strengthening the message that Obama is the candidate who can bring about "real change" in Washington.
With 53 days to go before November's general election, Obama's Campaign Manager David Plouffe sent a memo to reporters declaring "today is the first day of the rest of this campaign" against Republican rival John McCain, who has pulled ahead of Obama in some opinion polls this past week, reported dpa.
"We will respond with speed and ferocity to John McCain's attacks and we will take the fight to him," Plouffe said, but added that it would be "on the big issues that matter to the American people."
The tone of the election campaign has turned sharply negative over the passed few weeks especially in campaign ads as the polling gap between the two candidates has narrowed.
Some Democrats have expressed concern that Obama was not responding forcefully enough.
As if to answer the worry, Obama's campaign Friday released two new television ads that slammed McCain as "out of touch" with the concerns of ordinary Americans and aimed to recapture the change mantle for the Democrats.
With about 80 per cent of Americans believing the country is headed in the wrong direction after eight years under his own party, Republican McCain has been touting his ability to change a "broken" Washington establishment.
One Obama ad mocks the 72-year-old McCain for his inability to use a computer and email, showing images of a disco ball as McCain arrived in Congress in 1982.
"Things have changed in the last 26 years. But McCain hasn't," a narrator says. "After one president who was out of touch ... we just can't afford more of the same."
A second ad shows Obama speaking directly into the camera, arguing that "change is more than a slogan" and speaking of his own plans to shake up Washington.
Obama's anti-establishment message of bringing a new kind of conciliatory politics to Washington - "change you can believe in" - has been the cornerstone of his campaign since he announced his candidacy in February 2007. Obama was elected to the Senate in 2004.
But McCain, long known as a maverick for a seeking compromise and standing up to his own party, has emphasized his own image as a "reformer" in recent weeks in the hopes of distancing himself from President George W Bush.
His vice presidential pick Alaska Governor Sarah Palin, who earned a reputation for fighting corruption in both parties in her home state, reinforced that message.
Plouffe said the battle over who can bring about change "is a debate we welcome. It is the debate America needs."
Obama's running mate Joe Biden meanwhile released 10-years worth of tax returns on Friday in the interests of full "transparency," the campaign said.
Biden, who hails from a working-class background and is known as one of the poorest members of the US Senate, earned on average about 250,000 dollars per year, together with his wife Jill.