MANCHESTER, N.H.—Newt Gingrich's presidential bid is suddenly showing signs of life.

The former House speaker is adding staff in key states, opening new offices this week and raising more money than he has in months. And as his opponents suffer under the weight of high-profile missteps, Gingrich has captured the attention of both top rivals and hungry GOP voters, still reluctant to fully embrace former Massachusetts Gov. Mitt Romney.

Romney's staff concedes they're preparing for the emergence of a stronger Gingrich. But with the first states scheduled to begin voting in less than 60 days -- not to mention Gingrich's checkered personal history -- some Republicans say it may be too little too late.

Still, there is evidence of some momentum in a campaign thought considered all-but-dead a few months ago when most of his staff resigned.

"This summer we came close to not surviving. So I think there was a period there when it was reasonable to wonder what was going on," Gingrich said this week on Fox News Channel. "We are now methodically doing better and better."

Gingrich raised more than $1.2 million in October alone, aides said. That's not enough to keep pace with Romney, but it is more than Gingrich raised in July, August and September combined. And the flow of money appears to be growing.

In a fundraising message to supporters Thursday, Gingrich reported having already raised more than $500,000 in an effort to collect $1 million for the week.

He credits his modest rise to a rigorous debate schedule that has provided the former top House Republican with more than 10 opportunities to showcase a combination of feistiness, wit and command of the issues. Gingrich has been a prominent player in national politics and policy debates for nearly two decades.

Another six presidential debates are scheduled before the end of the year.

"There's so much fluidity in the race for second and third place, there's time for anyone to rise," said Jennifer Horn, a prominent conservative activist in New Hampshire. "Newt Gingrich knocks it out of the park in these debates, but he doesn't spend any time in the state. If he spent some time here, I think he has the opportunity to really take off."

Indeed, critics note Gingrich's reluctance to commit to the rigors of the type of traditional retail campaign his competitors have been running for months. He'll be on the road this week, however.

Gingrich is scheduled to attend a reception Friday in Manchester to celebrate the opening of his New Hampshire headquarters. He'll do the same Saturday in South Carolina, where he added nine paid staffers this week.

He'll also visit Iowa next week, where aides say they'll soon open a headquarters and add staff. Most of Gingrich's rivals hired staff and opened headquarters in early voting states months ago.

It's unclear when Gingrich will return to New Hampshire after Friday's reception. But he's planning to spend at least 30 days in Iowa in the closing weeks of the campaign, and has retained the backing of the handful of senior Iowa Republicans who endorsed him before the campaign turmoil.

"The energy behind Newt is growing at the right time," said Linda Upmeyer, Iowa's House majority leader, who endorsed Gingrich in February.

But as Herman Cain learned, the scrutiny that accompanies a more credible candidacy can be unforgiving.

Texas Gov. Rick Perry has struggled to meet lofty expectations after repeatedly stumbling in debates. And Cain is defending himself against several accusations sexual impropriety.

"If Newt keeps rising, they're going to start focusing on him. When they start opening his can of tuna, there's some juicy stuff there," said Peter Silva, the New Hampshire House majority whip and a Perry supporter.

Indeed, the twice-divorced Gingrich has admitted an affair with his current wife, Callista, a former congressional aide, while married to his second wife. It happened at the same time he was criticizing President Bill Clinton for his relationship with White House intern Monica Lewinsky.

In Boston, Romney's senior advisers anticipated it was Gingrich's turn to rise in the polls and said the former governor would be ready to debate policy with the former speaker.

Even so, no one at Romney's headquarters believed Gingrich would emerge as the consensus choice among Republicans looking for anyone but Romney. They privately pointed to his multiple marriages, his financially struggling operation and a shell of campaign that simply doesn't stack up in what could be a head-to-head contest.

But the Gingrich faithful are optimistic.

"Does the time work against us? Certainly it does," said Andrew Hemingway, Gingrich's New Hampshire state director. "But I'm truly shocked that there's so much support out there."

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Associated Press writer Thomas Beaumont in Iowa contributed to this report.

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