Mitt Romney’s first name is Willard, which means that he is actually “W. Mitt Romney.”

And it was a “W” that did him in Tuesday night.

In the middle of the second presidential debate, the one where Barack Obama had to do better and did, moderator Candy Crowley invited a question from Susan Katz, an undecided voter.

Katz admitted that she was “disappointed with the lack of progress I’ve seen in the last four years.” That sounded good for Romney, but then Katz added the “however…”

However, I do attribute much of America’s economic and international problems to the failings and missteps of the Bush administration. Since both you and President Bush are Republicans, I fear a return to the policies of those years should you win this election. What is the biggest difference between you and George W. Bush, and how do you differentiate yourself from George W. Bush?

There was never any question that Mitt Romney—who long ago abandoned the liberal Republican values of his parents—would throw the most recent Republican president under the bus.

That’s how Mitt rolls.

Unfortunately, he was so busy tossing Bush under the bus that he did not notice that it was dragging him down as well.

After being forced to answer the question by Crowley, Romney finally said that “President Bush and I are different people, and these are different times.”

For instance, Romney said, “I’ll crack down on China. President Bush didn’t.”

That was all Barack Obama needed.

“When [Governor Romney] talks about getting tough on China, keep in mind that Governor Romney invested in companies that were pioneers of outsourcing to China and is currently investing in…companies that are building surveillance equipment for China to spy on its own folks,” announced Obama. “Governor, you’re the last person who’s going to get tough on China.”

In the parlance of the Romney campaign, that was a “zinger.”

It stung because it had the ring of truth.

Again and again, on a night that saw Romney match the aggressiveness of his first debate performance, Obama stepped up. Instead of the listless performance that cost him so dearly in their initial encounter, this time the president was fighting.

When Romney abandoned the truth, as he did on a question about energy production, Obama abandoned the deference that had served him so poorly in the first debate.

“It’s just not true,” the president said of his challenger’s assertion.

Obama was not just fighting back, however. He was playing offense. On pay equity and immigration and tax policy, Obama called Romney out. But, despite an obsessive focus on the inevitable Libya question (and Romney's bumble on when Obama first said "acts of terror"), the portions of the debate that will matter are the ones where the president was defining his challenger as the Bain Capitalist that he is.

Referencing his challenger’s ever-changing positions on central issues of the campaign—such as tax cuts for the rich—Obama recalled the right-wing stances on economic and social issues that Romney so ardently embraced during the Republican primary campaign. “When Governor Romney stands here, after a year of campaigning, when during a Republican primary he stood on stage and said ‘I’m going to give tax cuts’—he didn’t say tax-rate cuts, he said ‘tax cuts’—to everybody, including the top 1 percent, you should believe him because that’s been his history,” Obama said.

“And,” he continued, “that’s exactly the kind of top-down economics that is not going to work if we want a strong middle class and an economy that’s striving for everybody.”

After Romney brought the issue up with a reference to wanting "100 percent of the American people to have a bright and prosperous future," Obama went for it:

I also believe that when he said behind closed doors that 47 percent of the country considered themselves victims, who refuse personal responsibility, think about who he was talking about: Folks on Social Security who have worked all their lives. Veterans who have sacrificed for this country. Students who are out there trying to hopefully advance their own dreams, but also this country's dreams. Soldiers who are overseas fighting for us right now. People who are working hard every day, paying payroll tax, gas tax, but don't make enough income.

"I want to fight for them and that's what I've been doing for the last four years. Because if they succeed, I believe the country succeeds," Obama continued. "When my grandfather fought in World War II and he came back and got a GI Bill that allowed him to go to college, that wasn't a handout—that was something that advanced the entire country and I want to make sure that the next generation has those same opportunities. That's why I'm asking for your vote and that's why I'm asking for another four years."

That was where the debate closed—on a winning note for Obama.

Obama was not always the debater that some of his supporters would have preferred. He did not, for instance, mount the sort of muscular defenses of Social Security and Medicare that Democrats such as Ohio Senator Sherrod Brown and Wisconsin Senate candidate Tammy Baldwin have made centerpieces of their campaigns this fall. That was politically tone-deaf, and practically worrying for progressives who fear that this president might be inclined to compromise on issues where he needs to fight.

The medium-cool president—who will never be confused with a full-on economic populist—did not begin to rip Romney as aggressively as he could have on the matter of the Republican nominee’s overseas investments and on Romney’s continued ties to the outsourcing machine that is Bain Capital.

Would that Obama had mentioned the circumstance in Freeport, Illinois, where Bain is this fall shuttering the advanced-technology Sensata plant and shipping the jobs to a client state in China.

But when Obama was on, he was very on.

In that same answer to the “W.” question, Obama focused on what for a lot of swing-state voters is and will continue to be the defining issue.

“When I said that we had to make sure that China was not flooding our domestic market with cheap tires, Governor Romney said I was being protectionist, that it wouldn’t be helpful to American workers,” said the president. “Well, in fact we saved a thousand jobs, and that’s the kind of tough trade actions that are required.”

That was a direct hit.

But the president was not done swinging.

[The] last point I want to make is this: You know, there are some things where Governor Romney’s different from George Bush. George Bush didn’t propose turning Medicare into a voucher. George Bush embraced comprehensive immigration reform. He didn’t call for self-deportation. George Bush never suggested that we eliminate funding for Planned Parenthood.

So there are differences between Governor Romney and George Bush, but they’re not on economic policy. In some ways, he’s gone to a more extreme place when it comes to social policy, and I think that’s a mistake. That’s not how we’re going to move our economy forward.

It was theme that Obama would return to again and again on a night where the president was talking to voters in swing states such as Ohio, which have been so hard hit by outsourcing.

After Romney made his big job-creation pitch, Obama acknowledged that “it’s estimated that that will create 800,000 new jobs.”

Then, with a smile, he added, “Problem is, they’ll be in China or India or Germany. That’s not the way we’re going to create jobs here.”

Obama was not speaking to Romney, nor to Candy Crowley on that one. He was talking to Toledo.

That’s politics. Smart politics.

Job creation wasn't the only tough economics question for Romney at last night's debate. Check out Ben Adler on Romney's opposition to equal pay for women.