By Matthew Davis
BBC News, Washington
The row over the legality of his domestic spying programme comes just as President George W Bush seemed to be making headway with his public relations offensive on Iraq and the war on terror.
The spying controversy comes as a critical time for the president
The apparent success of the Iraqi elections, opposition disarray and a slight upturn in poll numbers were all reasons for holiday cheer at the White House.
Yet the eavesdropping controversy has emboldened opponents and threatened his momentum.
So an impromptu news conference was a chance for Mr Bush to meet his critics head on and press his argument.
The president sounded confident and went on the offensive, saying he had the constitutional duty and authority to protect Americans.
Mr Bush said he had spoken to Congress on more than 12 occasions about the classified programme, but said its disclosure had been a "shameful act" at a time of war.
It is not a controversy that will fade away, however.
Members of Congress from both parties have suggested that the president has overstepped the powers granted to him.
Senators have pledged to hold hearings on the surveillance programme in the new year.
Democrat Senator Russ Feingold of Wisconsin said: "We will not tolerate a president who believes that he is the sole decision-maker when it comes to the policies that this country should have in the war against terror.
"He is the president, not a king."
All of this comes at a critical time for the president.
Not only is he trying to turn around creeping public dissatisfaction with Iraq and his presidency, he also needs to reassure Republicans ahead of the mid-term elections late next year.
Mr Bush's fellow party members do not want to be damaged at the polls by the issue of Iraq, or by concerns about how the president is running the war on terror.
Positive developments on the ground in Iraq during the next six months - like a reduction in the strength of the insurgency and the flourishing of democracy - will be crucial in this.
So too will be public perception of progress.
'Do not despair'
This is why Americans have seen so much of their president in the last few weeks.
Since late November Mr Bush has released a new plan for victory, held private meetings with sceptical members of Congress, and delivered four speeches setting out the details of his war strategy.
At the weekend, the president made his first live television address from the Oval Office since he announced the invasion of Iraq in March 2003.
In it, he struck a similar tone to his earlier speeches, more contrite than he has been in the past, more willing to admit mistakes, but no less determined to stay the course.
"I don't expect you to support everything I do but tonight I have a request," he said.
"Do not give in to despair and do not give up on this fight for freedom."
Stirring words, but for many Americans it will be events rather than speeches that have the most bearing on the battle for hearts and minds in 2006.