A while ago I wrote that President Obama did not seem to be having much fun. Now there’s a corollary: History has handed him a presidency that even the most exuberant tenant of the Oval Office might have a hard time enjoying.

And that has to affect how Obama thinks about the looming Aug. 2 implosion of the federal government.

Some readers took my first proposition as a jab at the president, which isn’t how I meant it. After all, the fact that he seemed like a normal, healthy guy who would rather spend Saturdays with his wife and daughters than with wealthy potential donors he hardly knew was one of the traits that attracted us to him in the first place. He was a rock star on the campaign trail, but (unlike, say, John Edwards) he didn’t seem to need the adulation for his own self-esteem. That seemed healthy, too.

Once in office, he was impatient with the trappings — photo ops with other world leaders, scripted readouts of bilateral summits — and unenthusiastic about golfing or drinking with politicians he didn’t much care for. His aggressively anti-LBJ style may have crimped his congressional relations, but to many of us it seemed pretty understandable.

What Obama did relish was surrounding himself with smart advisers, challenging them to come up with the best policy options for the biggest problems of the day and trying to push those into law. Which is precisely the line of activity that has been closed off to him during the second half of his first term.

One reason is the 2010 election that delivered the House to a relatively extreme Republican majority and a Democratic minority with electoral calculations that diverge from Obama’s for 2012; and delivered the Senate to a feckless and fractious Democratic majority and a united Republican minority unabashedly dedicated to his defeat.

Then there’s the deficit, which would rule out any Great Society initiatives even if Congress wanted to play along. Most of all, the economy and unemployment rate stubbornly refuse to follow Obama’s scenario for tangible improvement leading up to next year’s election.

The result is two years dedicated primarily to defense. His primary accomplishment, an initiative to guarantee health care for all Americans, is under assault in court and in Congress. Hopes to rewrite education policy hang by a thread. A grand, coherent response to climate change is beyond reach, with the president having to settle for modest administrative steps under the rationale of energy independence. As for a sensible plan to rebuild America’s roads and mass transit — forget about it.

Overseas, Obama seems to feel trapped by a war in a nation of little intrinsic strategic significance (Afghanistan), while initiatives he values more (nuclear nonproliferation, Arab-Israeli peace) stay stuck. (He has failed to seize the one major opportunity serendipity has offered — the Arab Spring — but that’s another story.)

And now, in the final year before presidential politics inevitably overwhelms everything else, he finds Washington obsessed to the point of mono-focus on what in past years has been almost routine: a vote to raise the nation’s debt ceiling.

So Obama’s focus has shifted to 2012. History would record a one-term president as a failure, whose signature accomplishment (health-care reform) could well be undone. Reelection would allow him to consolidate that reform and give him a second chance on others that now seem beyond reach.

To that end, the Aug. 2 deadline offers three potential strategies. One is to join Nancy Pelosi and go for broke on “Mediscare”: Accuse the Republicans of getting ready to wheel every granny out of every nursing home and otherwise threaten civilization as we know it.

A second would be to end up with Mediscare but first appear open to compromise, to appeal to independents, while assuming there can be no grand bargain with Republicans.

The third is to go for something real: a long-term debt reduction plan that would increase revenue, begin to control entitlements without threatening granny and reassure financial markets that the American political system can get its act together when push comes to shove.

After this weekend, option three is looking like a longer shot than ever. It may be that Obama missed his moment to make it work, when he shunned his Bowles-Simpson fiscal commission. It may be that the Republicans and his own liberal caucus always were fatally inclined toward intransigence.

But it’s also true that the political path to a $2 trillion deal doesn’t look all that much clearer than to a $4 trillion deal. And the bigger bargain still offers the biggest payoff. It would most enhance Obama’s chances for reelection. By controlling the national debt, it would give him in a second term the most scope for the kind of action that is off-limits to him today.

And, oh, yes — it would be the best outcome for the country, too.