President Obama has canceled campaign trips, convened high-level meetings with his top security and health advisers, and consulted with seven heads of state around the globe in an effort to contain the spread of Ebola. All in the past two days.

But all the scrambling has done little to reassure a jittery American public that the danger is contained or to stanch the political fallout, some of it from lawmakers in his own party, in the run-up to tough midterm elections next month.

Cognizant of the dangers that come from going before the public without answers, Obama has emphasized the low probability that the deadly disease will become a large-scale outbreak in the United States because it is not easily transmitted. But in the wake of acknowledged errors that led to the infections of two nurses in Dallas, the White House is now engulfed in a crisis that has resurrected questions about the president’s governing style.

After meeting with top aides in the Oval Office for nearly two hours Thursday night, Obama sought to address some of the criticism lawmakers have lodged against him by saying he may appoint one person, or “czar,” to oversee the federal response. But he reiterated that Americans remain safe.

“I understand people are scared,” the president said. “I do want everyone to understand it remains a very difficult thing to catch. The risks involved remain extremely low for ordinary folks.”

White House press secretary Josh Earnest was asked Thursday if President Obama was angry that another health-care worker was diagnosed with Ebola in the U.S. Earnest responded saying that some aspects of the response "have fallen short" of Obama's expectations. (AP)

White House senior adviser Dan Pfeiffer said in an interview Thursday the administration was seeking “a delicate balance” as it grappled with questions about how best to address the disease on American soil.

“We need to try to calm people because many people are fanning the flames here in a way that’s deeply irresponsible, but we also understand that there is real concern, and we’re trying to be sensitive to that,” Pfeiffer said. “That’s the balance we’re trying to strike.”

The vigorous public health debate has led to sharp political criticism for the president.

At a House Energy and Commerce Committee hearing Thursday, Majority Whip Steve Scalise (R-La.) said the Ebola issue had become a “major concern” for people across the country and a top issue in many congressional races. “It’s one more question about whether President Obama is up to the task of handling something like this; did he take it seriously enough, early enough?”

Even some of the president’s allies have questioned his approach. Rep. Bruce Braley (D- Iowa), who broke away from his campaign for the Senate to be at the hearing in Washington on Thursday, said he was “greatly concerned . . . that the administration did not act fast enough in responding” to the Ebola cases in Dallas.

Braley is in one of the most closely contested Senate races, and a Democratic loss in Iowa would severely harm chances that his party retain majority control of the Senate. Which could explain why White House press secretary Josh Earnest did not challenge Braley’s assessment, saying instead that the congressman “is somebody that has a reputation for being willing to speak truth to power, whether they’re in the same party as him or not.”

And even as Earnest emphasized the federal government was moving swiftly to address some of the problems that had led to the secondary infections at Texas Health Presbyterian Hospital Dallas, he acknowledged the president “believes that some aspects of this response have fallen short of his expectations.”

Since Saturday, the president and his aides have begun digging into the most granular aspects of public health, from the conditions of the two infected nurses to whether doctors with the Department of Veterans Affairs had infectious disease expertise they could share with other medical professionals.

One White House official, who spoke on the condition of anonymity, said Obama had been pressing his staff for answers on a variety of questions to not only treat the two health-care workers but to be prepared to handle future infections that Thomas Frieden, the director of the Centers for Disease Control and Prevention, and others have warned are likely to occur in coming weeks.

“These are all decisions, big and small, that he’s playing a hand in. This is not a situation that is resolved,” the official said, explaining why Obama had scrapped two separate campaign trips to the Northeast this week. “He wanted to be here to manage all that in real time.”

At the same time, Obama has been personally lobbying lawmakers against taking more drastic steps aimed at curbing the illness, such as banning all incoming passengers from the three West African countries most affected by the Ebola outbreak. Several senior Republicans, including House Speaker John Boehner (Ohio), have endorsed a travel ban, and on Thursday a handful of Democrats indicated they were open to the idea.

After a campaign event in St. Paul, Minn., Sen. Al Franken (D) said such restrictions should be implemented if the proper safeguards can be employed to allow for aid workers and other officials to access West African nations.

“We have to consider that,” Franken told reporters.

Also Thursday, three Virginia Republicans urged Gov. Terry McAuliffe (D) to use executive power to block entry into Virginia — notably through Washington Dulles International Airport — by anyone coming from an Ebola-ravaged country.

In a letter to the governor this week, Del. Robert G. “Bob” Marshall (Prince William), Sen. Richard H. Black (Loudoun) and Del. Mark J. Berg (Frederick) said McAuliffe should consider suing Dulles Airport or the federal government to ensure anyone suspected of bringing Ebola into Virginia is quarantined.

McAuliffe spokesman Brian Coy said the governor’s office is still working on a formal response to the Republican lawmakers’ letter.

Top administration officials who discussed the travel ban Wednesday with the president have rejected the notion of imposing such restrictions. Earnest and Frieden both emphasized that such a move would impede international efforts to stanch the spread of the disease at its source and that it could also worsen the problem by prompting infected travelers to either come into the United States through more circuitous routes or travel undetected to other countries. Both scenarios, they warned, could speed the virus’s spread.

Former Health and Human Services secretary Kathleen Sebelius, who headed the agency when the nation faced a deadly outbreak of the H1N1 virus — also known as swine flu — in 2009, recalled that the president was emphatic about only taking action when it was medically justified. At one point, policymakers debated whether to shut down the schools to protect children, who were disproportionately affected by the outbreak; experts cautioned that even though a vaccine was not available yet, it would be dangerous because exposure could rise as these same children moved about their neighborhoods in public places.

“There were people on both sides of the argument,” she said. “But he consistently said we have to make decisions based on the science, and then make decisions based on what we know and don’t know.”

The president also has no plans to remove Frieden, according to senior administration officials. One House Republican has called on Frieden — who has expressed regret that the CDC did not do more to prevent the secondary infections in Texas — to resign, but he remains widely respected within the public health community and has played a key role in guiding the administration’s response to the virus both overseas and at home.

The unknowns surrounding Ebola remain the most challenging aspect for Obama. During the Gulf of Mexico oil spill in 2010, the president and his top aides regularly briefed the media on their efforts to stop the oil gushing from the Deepwater Horizon, but it was not until BP capped the well months later that they could declare victory. In the more recent case of Islamist extremists in Syria, Obama came under withering criticism when he held a news conference and admitted he did not yet have a strategy for addressing the situation.

Now, the president and his aides are working behind the scenes to craft a long-term response to the virus, even as they know the public is looking for immediate results.

“We knew that every death would be a huge story and drive another round of panic,” Sebelius said of her time working on the swine flu epidemic. “It was very difficult to overcome one compelling terrible tragedy with facts.”

Paul Kane and Jackie Kucinich contributed to this report.