By ADAM NAGOURNEY


WASHINGTON - It’s not so easy being the loyal opposition these days.

Two months after Barack Obama’s election, Republicans are struggling to figure out how - or even whether - to challenge or criticize him as he prepares to assume the presidency on January 20.

The president-elect is proving to be an elusive and frustrating target. He has defied efforts to be framed ideologically. His cabinet picks have won wide praise. An effort by the Republican National Committee to link Mr.Obama to the unfolding scandal involving Governor Rod R.Blagojevich of Illinois and his alleged attempt to barter for Mr.Obama’s Senate seat was dismissed by no less a figure than Senator John McCain, the Republican Mr.Obama beat for the presidency.

The toughest criticism of Mr.Obama during this period - in fact, the only real criticism of him during this period - has come not from the right but from the left, primarily over his selection of the Reverend Rick Warren, an evangelical pastor who is a leading opponent of same-sex marriage, to deliver the invocation at the inauguration.

There are plenty of battles ahead that may provide Republicans with an opportunity. They will no doubt find arguments to use against Mr.Obama when, for example, he starts to lay out the details of his economic stimulus plans. Honeymoons tend to end.

Still, this display of Republican uncertainty is testimony to the political skills of the incoming president, and a reminder of just how difficult a situation the Republican Party is in. More than that, though, members of both parties say, it is evidence of the unusual place the country is in: buoyed by the prospect of the inauguration of a president who appears to enjoy great favor with the public, while at the same time deeply worried about the country’s future. It is going to be complicated making a case against Mr.Obama, many Republicans said, in an environment where people want him to succeed and may not have much of an appetite for partisan politics.

“I think the country is so tired right now of a style of Republican attack politics that has become a caricature of itself, they instinctively go,‘I’m tired of that,’”said Newt Gingrich, a Republican and former speaker of the House.“It’s ineffective against Barack Obama right now. The country is faced with serious problems and is about to have a brand new president. You’d have to be irrational not to want the new president to succeed.”

Saul Anuzis, chairman of the Michigan Republican Party and a leading candidate to become the next leader of the Republican National Committee, offered a similar message on his blog.“Where necessary,”Mr.Anuzis wrote, “we should stand for what is right and forcefully be the loyal opposition. But partisan politics in times like these for the sake of politics is not healthy.”

Republican leaders in Congress have made clear that they are looking, at least initially, to work with Mr.Obama, reflecting what they said was the seriousness of the times.

“You’ve seen very little criticism coming out of the gates of the president-elect or his cabinet selections,”Michael Steel, a spokesman for Representative John A.Boehner of Ohio, the House Republican leader, said.“We want to work with him on behalf of the American people and hope that he governs in the open and bipartisan way in which he promised.”

The presidential campaign clearly taught Mr.Obama how to avoid political mistakes and to clean them up quickly when made.

Beyond that, the historic nature of his presidency - of his being the first African-American president, and all the interest that has generated here and abroad - has complicated things even more for an opposition party looking to go on the attack.

The Republican National Committee appears to be having particular trouble in finding the right tone. Since Election Day, it has continued with the daily patter of attacks on Mr.Obama that it offered throughout the general election campaign, a strategy pushed by the national chairman, Mike Duncan, but one that clearly does not have universal support.

The committee’s effort to link Mr.Obama to the corruption investigation in Illinois, through statements and a television advertisement it produced, drew criticism from Mr.McCain as well as Mr.Gingrich.“It was amazingly wrong,’’Mr.Gingrich said.

For his part, Mr.Duncan, who is seeking re-election as chairman when the party gathers here in January, said there was a role for his party to act as “the loyal opposition: to ask questions, agree where you can, but ask questions all the time.”

Mr.Duncan suggested it would be easier after Mr.Obama took office.

“It’s too early,”he said.“We’re still in this honeymoon phase, and we will hold him accountable. We will work with him and try to make sure he keeps his promises.”