Barack Obama was tougher than John McCain on foreign affairs, clearer than him on remedying the sick economy, and drew a devastating comparison between his health plan and the frightening scheme offered by the Republican presidential nominee.

As was the case in their first debate, Obama emerged from Tuesday night’s confrontation in Nashville, Tenn., in command of the situation. The Democratic nominee looked calm, confident and presidential as he won their second contest.

McCain disregarded his running mate, Alaska Gov. Sarah Palin, who said he should “take the gloves off.” Neither was he the surly campaigner he had been on the stump when he demanded to know “Who is the real Barack Obama?” He still appeared amazed at Obama’s effrontery for even running against him. He grumbled and grouched. But somebody must have said, “John, be more civil,” and he took the advice, leaving Palin the job of tossing dirt, which she undoubtedly will eagerly accept.

McCain even came up with one pretty good idea in the debate. If elected, he said, “I would order the secretary of the Treasury to immediately buy up the bad home loan mortgages in America and renegotiate at the new value of those homes — at the diminished value of those homes and let people be able to make those … those payments and stay in their homes.

“Is it expensive? Yes. But we all know, my friends, until we stabilize home values in America, we’re never going to start turning around and creating jobs and fixing our economy. And we’ve got to give some trust and confidence back to America.”

This was McCain’s best moment of the evening. But the plan conflicted with something he had said just moments earlier: “We obviously have to stop this spending spree that’s going on in Washington.”

What was most striking about the debate was the difference between the two on chasing down Osama bin Laden in his Pakistan hiding place. Obama was clear and strong, showing determination and mastery. McCain was rambling. It was a bad moment for a candidate who boasts of his foreign affairs expertise.

Obama said, “If we have Osama bin Laden in our sights, and the Pakistani government is unable or unwilling to take them out, then I think that we have to act and we will take them out. We will kill bin Laden; we will crush al-Qaida. That has to be our biggest national security priority.”

That was too strong for McCain, and maybe for some of Obama’s more dovish supporters. McCain reflected the muddy thinking of the foreign policy establishment and the policy that led the United States to give billions to Pakistan’s then-President Pervez Musharraf while he made deals with the Taliban.

Also important were the candidates’ sharp disagreements on health care policy.

They had disclosed their contrasting plans many months ago. They have discussed them in speeches and in policy papers. But for a long time, nobody was listening — until the economy crashed.

On a Tuesday when the stock market dropped by 500 points and when retirement accounts faded away, thoughts of medical bills and unforgiving hospital bill collectors suddenly seemed more important.

Obama laid out his plan, a combination of affordable public and private insurance with companies forced to cover pre-existing conditions.

McCain offered his: ending tax subsidies to employers offering health insurance. Those receiving employer benefits would have to pay taxes on them. Instead, Americans would get tax breaks of $2,500 a person and $5,000 a family to use to purchase insurance.

Unfortunately, such plans run more than $12,000 for a family. And with the economy in such deep trouble, there will be fewer businesses offering health care. Good luck to anyone shopping for McCain-style health insurance.

This is a powerful issue for Obama and he ought to hammer McCain with it for the rest of the campaign.

At the end, the combatants got together. McCain didn’t shake Obama’s hand, but he guided his foe toward his wife, Cindy McCain, and she seemed friendly enough.

Now, the dirty stuff will resume. The Rev. Wright, Bill Ayers, the snide comments about Obama’s name, the unsubtle references to him being different — also known as African-American — abortion, the makeup of an Obama Supreme Court, each hit tailored to appeal to a different group of voters.

But all this seems small and unimportant compared to the calamities now reaching down into millions of American homes and businesses.