Returning to Washington from the campaign trail three weeks before midterm elections, Republicans made the call for a travel ban a dominant theme at a congressional hearing on the outbreak.
The Obama administration has resisted a ban on travel from Guinea, Liberia and Sierra Leone in West Africa, where thousands have died in the Ebola outbreak that began in March.
"The president has that authority. He's choosing not to exercise it," said Representative Michael Burgess, a Texas Republican. "No one understands why we're not doing this fundamental job of defending the country."
Obama, speaking to reporters on Thursday after a White House meeting with aides involved in the Ebola fight, said experts had told him "a flat-out travel ban is not the way to go" because a ban would be less effective than current screening measures on travelers to the United States from the region.
"I don't have a philosophical objection necessarily to a travel ban if that is the thing that is going to keep the American people safe," Obama said.
But he noted that some travelers might try to enter the United States under the radar and would avoid the screening measures, leading possibly to more rather than fewer Ebola cases.
During the House subcommittee hearing, lawmakers from both parties criticized the administration's handling of the Ebola outbreak in the United States and said public trust in the response was dwindling.
But that loss of trust has also fueled Republican charges of administration incompetence, particularly in light of recent embarrassments like the Secret Service's failure to keep a man with a knife from running into the White House and a cover-up of waiting list delays at Veterans Affairs hospitals.
"Distrust in government is even greater now that Ebola has crossed into our country after the president said it was unlikely. My constituents are saying that 'this is a problem,'" U.S. Representative Dennis Ross, a Florida Republican, told Reuters in a telephone interview.
A traveler from Liberia, Thomas James Duncan, became the "index patient" in Dallas, dying from the disease. Two American nurses treating him became infected, in spite of government assurances the U.S. medical system could handle Ebola.
'WE HAVE TO PROTECT OURSELVES'
Public alarm has since spiraled, even among Americans far from anywhere they could have been exposed.
"We have to protect ourselves," said Sadie Edmondson, 71, standing outside the laundry she runs in Goldsboro, North Carolina, explaining why she wanted a travel ban. "A lot of these people may not even know yet that they have it. Or they may not be telling us that they’ve been exposed."
Nearly half of Americans said they were avoiding international air travel because of Ebola, a Reuters/Ipsos poll showed.
The growing concern and the chorus of Republican criticism of the president come less than three weeks before elections in which Republicans hope to pick up the six seats they need to regain a U.S. Senate majority.
Colorado Republican Cory Gardner and Iowa Democrat Bruce Braley, both locked in tight races for critical U.S. Senate seats, were prominent among the lawmakers who swapped the campaign trail for the hearing room.
House of Representatives Speaker John Boehner has also urged Obama to consider a travel ban.
Dr. Thomas Frieden, director of the U.S. Centers for Disease Control and Prevention, told lawmakers a ban could make the crisis worse. He said some West Africans had U.S. passports and that others could come into the country without revealing their points of origin, making it harder to trace them.
Representative Henry Waxman, a California Democrat, waved a map showing air traffic patterns from the Ebola zone to argue that a ban would not keep out passengers traveling through third countries.
Federal Aviation Administration chief Michael Huerta told reporters separately that the United States was assessing whether to issue a travel ban "on a day-to-day basis."
Away from Capitol Hill, Louisiana Governor Bobby Jindal, seen as a 2016 Republican presidential hopeful, said people should be added to the anti-terrorist "no-fly" list to stop them from flying to and from countries in West Africa.
"Even though it makes common sense to do this, the White House has refused to do it," he said in a statement.
At least 40 members of the Senate and House, almost all Republicans, have called for travel bans or demanded that the State Department stop issuing visas to citizens of Liberia, Sierra Leone and Guinea.
Over two dozen lawmakers, only three of them Democrats, wrote to Obama last week asking the State Department to ban travelers from the affected countries and restrict visas.
The lawmakers gave few details about their proposed bans. Most did not say whether they would apply to U.S. citizen or how they would handle dual citizens. Some, but not all, suggested military personnel and health workers should be exempted.