President Obama touted a series of lame-duck legislative victories as an example of the bipartisan cooperation possible next year, when Republicans control the lower chamber.

During a Wednesday afternoon press conference, a visibly happy president offered high praise for a string of bills that passed during the post-election session of Congress.

"I think it's safe to say this has been the most productive post-election period we have had in decades," he said. "We are not doomed to endless gridlock."

He also urged Republicans not to cause a stalemate when they assume control of the House, and a larger minority in the Senate, when the 112th Congress convenes in January 2011.

He cautioned the GOP that he would not be a pushover, even though he again acknowledged that his party took a "shellacking" in the midterms.

"One thing I hope people have seen in this lame-duck: I am persistent," he said. "I am persistent. If I think something's important, I stay on it."

After suffering historic defeats in the November midterm elections seven weeks ago, Obama took the opportunity to climb back onto his feet by extolling the passage of his tax-cut deal, the repeal of "Don't ask, don't tell," legislation providing healthcare compensation for 9/11 first responders and a nuclear arms reduction treaty with Russia he called his "most significant national security priority."

But Obama's victories over the past several weeks don't necessarily indicate he will have the same level of success next year. GOP lawmakers have said the results of the elections show that voters want the Obama administration to scale back its agenda.

Obama — who departed the conference to join his family on vacation in his home state of Hawaii — admitted that both sides will need to compromise, but that he still would press Congress to pass his priorities.

The president acknowledged both political parties will have sharp disagreements over issues like taxes and spending under a divided government. But he expressed confidence that both sides could work together next year, saying that Republicans have nearly as much to lose as he does if the government struggles to pass legislation that aids the economy.

"I am not naive. I know there will be tough fights ahead," he said. "Both parties will be held accountable. ... I think the Republicans realize that with greater power comes greater responsibility."

The president did express serious disappointment over the failure of controversial immigration legislation known as the DREAM Act.

He said its demise in the Senate was "maybe the biggest disappointment" of the 111th Congress, mentioning energy legislation as well.

But the president reiterated he would not back down in the face of widespread Republican opposition.

"I'm going to go back at it," he said.