FAYETTEVILLE, N.C. — Barack Obama strongly boosted his presidential prospects yesterday, winning the coveted endorsement of former Secretary of State Colin Powell and ringing up $150 million in contributions in a single month of fundraising.

The endorsement from one of the country's most respected statesman-soldiers enhances Obama's credibility on national security issues, while his huge cash haul allows him to extend his critical advantage on the television airwaves.

The Illinois senator's showing came as he continued to drive deep into Republican territory, stumping in North Carolina, which has not backed a Democrat for president since 1976. John McCain campaigned yesterday in must-win Ohio, where polls show a close race, and spent part of the day defending the qualifications of his running mate, Sarah Palin, on national television and in a conference call with Jewish leaders.

The day's main stage, however, was a TV studio in Washington, where the retired Army general ended months of speculation by crossing party lines to support Obama, who is vying to become the nation's first black president.

"I think he is a transformational figure. He is a new generation ... coming onto the world stage, onto the American stage, and for that reason, I'll be voting for Sen. Barack Obama," Powell said on NBC's "Meet The Press."

Given his credentials — as secretary of state for President Bush, chairman of the Joint Chiefs of Staff under Bush's father and national security adviser to President Reagan — Powell's vote of confidence might allay concerns about Obama's readiness to be commander in chief, one of the Republicans' chief lines of attack.

For all its potency, however, Powell's endorsement might have been only the second-most important political development of the day, coming hours after the Obama campaign announced its latest fundraising total in an e-mail to supporters.

The $150 million figure shattered the previous monthly record and, combined with the $49.5 million raised by the Democratic Party in September, gives Obama a gargantuan financial advantage over McCain with just more than two weeks to go.

Obama has a 2-to-1 cash advantage over McCain, who accepted $84.1 million in federal funding for the fall campaign and can spend no more than that amount. Obama initially said he would accept public financing if McCain did but changed his mind after his strong fundraising performance in the primaries.

By opting out of the government financing system — and becoming the first major-party candidate to do so since it was set up in 1976 — Obama is free to raise and spend unlimited sums. Overall, Obama has raised a record $605 million.

Powell, 71, who once considered his own history-making bid to become America's first black president, said he reached his decision after closely observing Obama and McCain over the past two months. He said the GOP nominee did not seem to grasp the depth of the global financial crisis and appeared to offer shifting solutions to the problem.

He called Alaska Gov. Palin, "a distinguished woman" but added, "I don't believe she's ready to be president ... which is the job of the vice president."

McCain said he was not surprised by Powell's decision. "We have a respectful disagreement," he said on "Fox News Sunday."