As political gridlock again threatens Washington with government shutdown, President Obama faulted Republicans' election year "lurch into extremes" for keeping compromise out of reach.
"You know, you never want to say, 'It's all them,'" Obama said in an exclusive interview with ABC News' Barbara Walters. "But I do think that right now at least, in the Republican Party there are a couple of notions. Number one is that compromise is a dirty word. Number two, anything that Obama's for, we're against."
The full interview can be seen during a "20/20" holiday special on Friday, Dec. 23, 10 p.m. ET on ABC stations.
The president pointed to the ongoing fight over Democrats' health care overhaul as an example of what has gone awry, calling out his top two potential Republican challengers for having previously supported elements in his plan.
"If I propose a health care bill that is full of Republican ideas -- in fact, is very similar to the law that was passed by the current Republican front runner, or one of the top frontrunners ? the other guy was supportive of many of the ideas as well -- suddenly, they become against it," he said.
Gingrich in 2007 called on Congress to create a national health insurance exchange, health savings accounts and "require anyone who earns more than $50,000 a year to purchase health insurance or post a bond." He has since called the idea of an individual mandate "unconstitutional."
In 2006, then-governor Romney signed into law health care legislation that required state residents to obtain a health insurance plan or face a penalty and provided subsidies to some who couldn't afford insurance. Both elements are part of Obama's plan.
"I do think those dynamics are making it more difficult to get things done," Obama said. "And it's not unusual, after such a severe economic crisis like this, for the politics to be impacted by that, for people to lurch into extremes, or to get more combative."
The inability of Democrats and Republicans in Congress to compromise, fueled in part by pre-primary rhetoric on the campaign trail, is threatening for the third time this year to shut down the government this weekend if both sides can't reach a deal on a spending bill and payroll tax cut extension.
Meanwhile, unfavorable views of Obama have hit an all-time high, according to the latest ABC News/Washington Post poll.
"Does that suggest that the American people find you a mediocre president?" Walters asked Obama.
"I think what it suggests is that we've gone through a very difficult time. And, in order for us to move forward, we're going to have to do more work," he said.
"So, you won't be a mediocre two-term president? " Walters asked.
"I want to be a really good two-term president," Obama said. "I think that the choices we've made have made America stronger, and have made the American people... put them in a better position in order to succeed over the long term. Short term, folks are still hurting."
When asked whether he believes scrutiny of a candidate's marriage history should be part of the process during the 2012 presidential campaign, Obama seemed to pull back.
A candidate's domestic fidelity has become an issue in the GOP primary race as Gingrich's rivals have suggested his three marriages are suggestive of a person whose loyalty can't be relied upon.
"I'm not big on someone's personal lives being poked and prodded and that ends up being the primary issue," Obama told Walters. "We've got such big issues to deal with right now, and there are such substantial differences between certainly my position and any of the Republican candidates. That's what we should focus on."
Turning from campaign politics to a major milestone in Iraq, Obama lavished praise on military service members who formally lowered the flag on the U.S. mission there after nearly nine years.
"Our troops are coming home with their heads held high, because despite an extraordinarily difficult situation, because of their sacrifice and their skill, they are handing over to Iraq a country that has had a democratic election, that is working in a political fashion instead of a violent fashion to solve differences," Obama said.
But Obama stopped short from characterizing the U.S. effort in Iraq as "victorious."
"I would describe our troops as having succeeded in the mission of giving to the Iraqis their country in a way that gives them a chance for a successful future," he said.
President Obama Talks With Barbara Walters
Obama, who did not support the U.S. invasion of Iraq in 2003 and called it a "dumb" war, pledged during his presidential campaign to initiate an end to the conflict immediately upon taking office. He's spent the last few months making a point of underscoring the promise kept.
"One of the most extraordinary chapters in the history of the American military will come to an end," Obama told troops at Ft. Bragg on Wednesday. "Iraqis future will be in the hands of its people. America's war in Iraq will be over."
In August 2010, Obama announced an end to combat operations in Iraq, and in October he said that all U.S. troops would be withdrawn by the end of this year.
Today, in a small ceremony in Baghdad, the U.S. military formally lowered the flag on its mission there after nearly nine years.
The war cost taxpayers more than $800 billion, according to Defense Department estimates. Nearly 4,500 Americans were killed in the fighting along with tens of thousands of Iraqis. More than 32,000 U.S. service members were wounded in action.
"History will judge the original decision to go into Iraq," Obama said during a press conference Monday. "But what's absolutely clear is, as a consequence of the enormous sacrifices that have been made by American soldiers and civilians ? American troops and civilians ? as well as the courage of the Iraqi people, that what we have now achieved is an Iraq that is self-governing, that is inclusive, and that has enormous potential."
Walters' wide-ranging interview with the president and first lady today at the White House is their only joint network television interview this year. Excerpts will air tonight on "World News with Diane Sawyer" as well as on ABCNews.com and Yahoo! as part of the "Newsmakers" series. The full interview can be seen during a "20/20" holiday special on Friday, Dec. 23, 10 pm ET on ABC stations.