U.S. President Barack Obama said this week that his administration has to do a better job of dealing with terrorism threats in the wake of the failed Christmas Day bomb plot aboard a commercial flight en route to Detroit. Opposition Republicans have been critical of the administration's handling of the incident, and political experts have been assessing the fallout.

The failed terror bomb plot constitutes Mr. Obama's most serious national security test to date, and the president has been quick to acknowledge that there is plenty of room for improvement.

"So we have to do better, and we will do better," he said. "And we have to do it quickly. American lives are on the line."

Opposition Republicans see an opening in the administration's flawed handling of the failed attack, and appear eager to highlight the incident as a potential campaign issue for the November midterm congressional elections.

Republican National Committee Chairman Michael Steele spoke on NBC's Today program.

"At some point this administration has to take responsibility for what it is doing and take responsibility for its decisions," he said. "They are having an impact, whether domestically or internationally, and you have got to account for it, and this is one of those break points where you stop and assess how is the administration doing? How are they performing?"

The failed bomb attack has given the U.S. public a chance to see how the new president responds to a national security threat, says University of Virginia political analyst Larry Sabato.

"Obama is seen as a domestic policy president, somebody without much foreign policy or national security experience, and Americans naturally wonder and maybe worry about how he is going to deal with those issues," he said. "So, when an event like this occurs, it is incumbent upon a Democrat to react quickly and decisively, and Obama failed to do it."

Mr. Obama's handling of the Christmas Day incident has sparked comparisons with his predecessor, former President George W. Bush. While Mr. Bush was clearly unpopular toward the end of his eight years in office, Americans generally had confidence in his ability to handle the threat of terrorism.

Author and political analyst Richard Wolffe was a guest on VOA's 'Issues in the News' program.

"One of the jobs of the president, whether you are named Bush or Obama, is to go out there and reassure people and to show you are in charge and to send a signal to potential enemies out there that this will not be tolerated by any American leader, and they did not project that power effectively," he said.

Mr. Obama won the presidency in 2008 largely because of the public's desire for change and concerns about the domestic economy. But a shift in emphasis to security issues offers a new set of challenges for the president.

Matt Dallek is a political historian at the Bipartisan Policy Center in Washington.

"National security was not the biggest issue," he said. "I think the economy emerged. And so I think they are concerned that on national security the Republicans could get the upper hand and hurt Obama politically."

The national security challenge comes at a difficult time for Mr. Obama, who later this month will mark his first year in office.

The president's signature domestic policy initiative, health care reform, faces one last round of congressional negotiation and debate before approval. And mixed economic signals continue to call into question how long it will take for the country to emerge from recession.

Mr. Obama began his term with soaring approval ratings in public opinion polls. But those ratings have steadily eroded in recent months, says analyst Larry Sabato.

"He is at 50 [percent] or below in most surveys, and that is mainly because of the economy, which continues to be stubbornly weak, the unemployment rate is very high and still in double-digits, and as a consequence Obama doesn't have much margin for error," he said.

Despite the problems, Mr. Obama remains personally popular, even if voters do not approve of his policies. And Republicans have their own challenges trying to find new leaders and craft a cohesive message beyond simply opposing the president and his policies.

Darrell West is with the Brookings Institution in Washington.

"President Obama continues to inspire great confidence from the American public, especially when you compare him to other political leaders," said West.

That confidence will likely be put to the test as the administration's review of its handling of the failed bombing attack unfolds in the weeks ahead.

on the line:处于危险中

incumbent: imposed as an obligation or duty; obligatory 负有职责的，义不容辞的

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（来源：VOA 编辑：陈丹妮）