(AP) - Barack Obama, launching his historic fall campaign for the White House with an outdoor Democratic National Convention extravaganza, pledged Thursday to "fix the broken politics inWashington" after he defeats Republican John McCain in the fall.

"We are better than these last eight years. We are a bettercountry than this," Obama said in excerpts of his acceptancespeech released in advance of his speech.

Seeking to weld his Republican rival to the outgoing Bushpresidency, Obama declared that McCain as a senator had voted withBush 90 percent of the time. "I don't know about you, but I'm notready to take a 10 percent chance on change," he said.

"We meet at one of those defining moments - a moment when ournation is at war, our economy is in turmoil and the Americanpromise has been threatened once more," Obama said in theexcerpts.

He said it's time to change leadership in Washington after twoterms of the Bush administration. "On Nov. 4," he said, "we muststand up and say: 'Eight is enough."

Obama said that more Americans now are out of work or workingharder for less, more have lost homes or are watching home valuesplummet, have cars they can't afford, credit card bills they can'tpay and tuition that is beyond reach.

"These challenges are not all of government's making. But thefailure to respond is a direct result of a broken politics inWashington and the failed presidency of George W. Bush," he said.

Obama said he was setting a goal "for the sake of our economy,our security and the future of our planet," of ending dependenceon oil from the Middle East in ten years.

Playing on Bush's assertion in his 2007 State of the Unionaddress that the nation was "addicted" to foreign oil, Obamasaid, "Now is the time to end this addiction."

Obama also sought to ease any concerns Americans might have thathe was not prepared to be commander in chief or that Democrats werenot as trustworthy as Republicans on national security.

"We are the party of Roosevelt. We are the party of Kennedy. Sodon't tell me that Democrats won't defend this country. Don't tellme that Democrats won't keep us safe," Obama said.

"The Bush-McCain foreign policy has squandered the legacy thatgenerations of Americans - Democrats and Republicans - have built,and we are to restore that legacy," he said.

"As commander in chief, I will never hesitate to defend thisnation, but I will only send our troops into harm's way with aclear mission and a sacred commitment to give them the equipmentthey need in battle and the care and benefits they deserve whenthey come home," he said.

For an interview with Rep. John Hall from Democratic National Convention, go to your digital cable box and select iO Extra, Channel 612.