Obama will return to full campaign mode on Thursday with events in Wisconsin, Colorado and Nevada -- all still up for grabs and therefore crucial to both candidates. His intention Wednesday was to project the image of a president focused on the well-being of fellow citizens in need.

After flying over parts of the Jersey shoreline and other areas, Obama and Christie met with displaced people in a shelter and later walked through damaged neighborhoods in an entourage that included the state's two Democratic senators - Frank Lautenberg and Bob Menendez.

On Tuesday, Christie praised Obama as "outstanding" and "incredibly supportive" in responding to Sandy, a radical change from the political attacks the Republican usually launches in his role as a top surrogate for Romney.

The governor repeated his complimentary tone while with Obama on Wednesday, saying: "I cannot thank the president enough for his personal concern and compassion for our state and the people of our state."

Hard-hitting attacks from candidate supporters

Meanwhile, supporters of the candidates continued hard-hitting attacks.

Priorities USA Action, a super PAC backing Obama, announced a new ad accusing Romney and former Florida Gov. Rick Scott, a fellow Republican, of benefiting from Medicare fraud.

"While Romney served as a director of the Damon Corporation, the company stole $25 million from Medicare," said a release by Priorities USA Action, attributing the information to a Boston Globe report from 2002. "Romney made half a million dollars - some of the profit generated by the fraud. Rick Scott was CEO of the company that committed what was the largest Medicare fraud in history."

The group also said Romney plans to cut funding for Medicare and change it to a voucher system that would increase costs for senior citizens. Romney rejects that characterization of a proposal to partially privatize the government-run health care system for elderly Americans.

There was no immediate response from the Romney campaign to the super-PAC ad.

Florida, with 29 electoral votes, is the biggest haul available from the battleground states still contested, and Medicare is a major issue there because of the large number of senior citizens who live there.

For its part, the Romney campaign revived a widely-discredited welfare claim in a new television ad that cited the "gutting" of the work requirement in welfare by Obama.

An earlier string of ads making a similar claim was rated as "Pants on Fire" -- or completely false -- by the independent and non-partisan fact-checking organization PolitiFact.

Obama campaign spokeswoman Lis Smith responded that the welfare ad showed desperation by the Romney campaign.

Meanwhile, Focus on the Family, the Colorado-based social conservative organization founded by evangelical author and radio host James Dobson, sent a mailing in Iowa that quotes Obama as saying "we are no longer a Christian nation."

The fold-out brochure, which landed in Iowa mailboxes last week and was provided to CNN by a Des Moines-area voter, drew contrasts between Obama and Romney on the issues of abortion, same-sex marriage and insurance coverage for contraception.

"Whatever we once were, we are no longer a Christian nation," Obama is quoted as saying in the mailer, which does not explicitly endorse Romney.

The quote is from a speech Obama delivered in 2006, more than two years before he became president, at the Call to Renewal conference in Washington.

In 2008, during Obama's first national campaign, the same out-of-context remark was circulated online as sinister evidence that the Democrat intended to curtail religious freedom in America. At the time, the spurious Internet chatter was debunked by FactCheck.org, another independent monitoring group.

Big ad buys in final week

The Obama and Romney campaigns bought $40 million worth of commercials to run this week and into Election Day in key battleground states, according to a source tracking media buys, as spending records continue to be shattered.

For ad time running from Monday through the November 6 election, the Obama campaign bought $22.6 million compared to $17.4 million for Romney, according to the media-tracking source. Both campaigns are continuing to purchase additional commercial time as they jockey for any last-minute advantage.

In addition, two of the key super PACs backing Romney launched multi million-dollar battleground ad campaigns this week, with many of their ads targeting the president's economic record. In total the Republican outside groups will have spent more than $310 million in the general election.

At Romney's event in Tampa, Bush sought to downplay Obama's role in the disaster relief effort, saying "my experience in all this emergency response business is that it is the local level and the state level that really matters."

"If they do their job right, the federal government part works out pretty good," he said.