Mitt Romney says Obamacare has ruined Obama's second term. Is he right?

Presidential second terms are a tough business. Ronald Reagan had the Iran-Contra scandal. Bill Clinton had the House of Representatives impeach him over the Monica Lewinsky affair. And George W. Bush saw his approval rating drop from 45 to 28 percent as the economy crashed and the war in Iraq lingered.

So President Obama was facing a tough task anyway.

Then came the Obamacare rollout.

With ill-disguised glee, Mr. Obama's opponent in the 2012 presidential election, Mitt Romney, told NBC's "Meet the Press" Sunday that the Obamacare debacle "has undermined the foundation of [Obama's] second term."

Specifically, Mr. Romney was referring to the promises made by Obama that Americans who liked their current policy could keep it – something that is proving untrue for 7 million to 10 million people. And Romney's insinuation is clear: I wouldn't have done things this way.

Still, there is perhaps a bit too much truth in Romney's statement for Obama's liking.

Immigration reform? New federal stimulus to create jobs? No one is talking about those now. In fact, no one is talking about anything that Mr. Obama wants to talk about now because America is gripped by uncertainty about the Affordable Care Act that is the centerpiece of his presidential legacy.

How many people will be driven off their plans? Will health-insurance premiums rise or fall for most Americans? Will the health exchange website where people can shop for new insurance plans be accessible by the end of November as the White House promises? What happens if it isn't?

And so on.

At this point, we're not even quite sure what Obama's broader goals for a second term agenda are, aside from getting his eponymous health care law to a state approaching functionality.

As we noted, this is hardly a problem unique to Obama. To the contrary, it has become a second-term rite since Richard Nixon resigned amid the Watergate scandal. For Obama, that pattern had already become apparent earlier this year. Republicans in Congress were hammering him over the 2012 attack on the American consulate in Benghazi, as well as reports that a section of the Internal Revenue Service was targeting tea party groups.

The inviolable law of every presidential second term is that it was followed by a first term, and that gives political opponents four years of missteps and secret documents to mine into partisan political gold. Second-term agendas are killed in just such a way.

Yet for the moment, the White House is doing the Republicans' work for them. The Republicans tried – and abjectly failed – to turn Obamacare against the president. Their government shutdown and debt-ceiling standoff backfired, public opinion polls showed.

Now, opinion polls show that the Obamacare rollout is backfiring on the president himself.

"The latest Christian Science Monitor/TIPP poll shows Obama’s Presidential Leadership Index – which combines job approval, leadership, and favorability ratings – is at an all-time low of 43 (where a score of 50 is neutral)," Monitor reporter Linda Feldmann wrote Friday. Other polls show a similar trend.

In truth, Obamacare has backfired on the president before. It was the spark that kindled the tea party rebellion in the 2010 midterms. The unruly Republican House, which has stymied virtually every major piece of Obama-backed legislation since 2010, is in many respects the product of the anti-Obamacare backlash.

Why do you think the Republicans in the House have been so eager to undo the law? Because they were sent to Washington precisely to do it.

Now, as Obama stares ahead likely to another three years of fighting the Republican House majority that he played a role in creating – and which will certainly oppose his second-term agenda at every turn – the urgency to get Obamacare right becomes plain.

It's not at all certain that Republicans will give him the chance to do anything else.