You could tell as much from the contrast between his petulant postelection press conference and his peppy pre-Christmas press conference. In the former he was crabby about accepting Republicans' demands that income tax rates on all taxpayers not be raised. In the latter he was celebrating the lame-duck Congress' acceptance of his stands on the New START treaty, repeal of "don't ask, don't tell," and even the previously reviled tax deal.
Obama has obviously figured out that Americans prefer to see their president describe the glass as half full rather than half empty. That's a good lesson for him, and for Republicans as well, especially those who believe that the Obama Democrats' shellacking in the midterms means that Obama himself will definitely lose in 2012.
History should provide some caution for these folks. Jimmy Carter and George H.W. Bush saw their parties fare pretty well in their midterm elections. But they were defeated for re-election anyway.
In contrast, pundits thought that Ronald Reagan's Republicans took a shellacking in 1982 (actually, about half their losses resulted from redistricting) and Bill Clinton's Democrats definitely did in 1994. But both the 40th and 42nd presidents were resoundingly re-elected, carrying 49 and 31 states.
Several factors will likely work less strongly against Obama in 2012 than against the Obama Democrats in 2010. Turnout will be different, for one thing. We may see again the record turnout of blacks we saw in 2008. Young people who pretty much shunned the polls in the midterms may turn out and vote -- though the 34-point margin they gave to Obama was halved to 17 points for congressional Democrats in 2010.
The balance of enthusiasm favored Republicans and conservatives in 2010, as it had favored Democrats in 2006 and 2008. It could conceivably shift and favor the Democrats once again.
Another factor is that polls show that most Americans have favorable personal feelings toward the president. Bill Clinton and George W. Bush both happened to have personal characteristics that people on the other side of the cultural divide absolutely loathed. Obama doesn't.
His reliance on his teleprompter, his secret smoking, his irritability when not adored -- these are pretty minor failings. People like his family and his obvious devotion to them. They don't mind that he likes to get away and play golf or shoot hoops from time to time.
Then there is the powerful desire Americans have to see their presidents succeed. That worked for Bill Clinton in 1996 and George W. Bush in 2004. Polls and focus groups showed that voters in the middle of the political spectrum were ready to overlook their weaknesses and appreciated their strengths in those years. That could be the case with Obama in 2012.
Moreover, there will be a reluctance on the part of many voters, understandable in light of our history, to reject the first black president. I'm convinced, though I cannot prove, that Americans who feel this way far outnumber those few who cannot abide seeing a black man in the White House.
All of which does not mean that Obama is a sure winner. Polls suggest that if the election were held today he could lose to several possible Republican nominees who are much less well known and have weaknesses of their own. But they also suggest he could win.
Working against Obama still will be substantive issues. Most Americans want to repeal Obamacare; he wants to keep it. Most voters rejected his vast expansion of the size and scope of government; he still thinks it's a good idea.
Obama came to office with the assumption that economic distress would increase support for his policies to (in his words to Joe the Plumber) "spread the wealth around." But the 2010 midterms make it about as clear as these things can be that voters reject such efforts.
American voters are not seething with envy over income inequality and are not convinced that we'll all do better if the government takes away more of Bill Gates' money. Obama, like the academics in whose neighborhoods he has always chosen to live, think they should be seething and that if the message is just delivered the right way they can be convinced.
That's a big difference on some fundamental issues. Enough to make the difference in 2012? Not clear.
Michael Barone,The Examiner's senior political analyst, can be contacted at email@example.com. His column appears Wednesday and Sunday, and his stories and blog posts appear on ExaminerPolitics.com.