But how much will Libya resonate with voters who place the economy atop their list of concerns?

Even Portman acknowledged that foreign policy only ranks "probably 7 or 8 or 9" on the list of issues voters deem important. Still, he argued, it's one more chink in the armor for a president running neck-and-neck with his challenger.

3. Obama throws the briefing book at Romney

If Obama didn't glance at his briefing book before the Denver debate, he definitely did this time.

From the outset, Obama sounded like he was sending a bouquet to his rapid response team in Chicago, a group of hard-charging staffers that pushes anti-Romney stories to campaign reporters on a daily basis.

Answering the first question of the debate, which was about jobs, the president unloaded on the Republican nominee, saying, "when Governor Romney said we should let Detroit go bankrupt, I said we're going to bet on American workers and the American auto industry and it's come surging back."

That was soon followed by a scathing attack on the former Massachusetts governor's signature economic plan.

"Governor Romney doesn't have a five-point plan. He has a one-point plan. And that plan is to make sure that folks at the top play by a different set of rules," claimed Obama.

And the president attacked Romney's proposals to reform taxes and lower the deficit.

"Governor Romney was a very successful investor. If somebody came to you, governor, with a plan that said, 'Here, I want to spend $7 or $8 trillion, and then we're going to pay for it, but we can't tell you until maybe after the election how we're going to do it,' you wouldn't take such a sketchy deal and neither should you, the American people, because the math doesn't add up."

Then there was this zinger on outsourcing: "Governor, you're the last person who's going to get tough on China."

Obama also criticized Romney over the rate he pays on his federal taxes, his stance on health care coverage for contraception and his calls to cut federal funding for Planned Parenthood, his plans to reform Medicare, and his support of Arizona's controversial illegal immigration law. The reference to Romney's "47%" controversy came just before the closing bell.

The president sure seemed like he was trying to make up lost ground following his lackluster performance in the first presidential debate two weeks ago.

The Obama campaign claimed victory.

"You saw Governor Romney backpedaling all night, you saw him defensive, in some cases stammering, trying to explain his plans," senior Obama campaign adviser David Axelrod told reporters after the debate. "It was a dominant performance because the president pulled the curtain back on this bait-and-switch of Mitt Romney."

The Romney campaign disagreed.

"I think President Obama came in and overcompensated," senior Romney campaign strategist Stuart Stevens said. "There's a difference between showing passion and showing you having a plan."

What did people who watched the debate think?

By a 49%--35% margin, debate watchers questioned in a CNN/ORC International poll said that Obama spent more time than Romney attacking his opponent. And nearly three-quarters said the president performed better than expected.

Maybe the president took note of Vice President Joe Biden's aggressive debate performance in last week's vice presidential showdown with GOP runningmate Rep. Paul Ryan. Regardless, we learned that Obama was able to step it up when it mattered the most.

4. These guys don't like each other very much

It's pretty obvious -- Obama and Romney don't like each other.

Need more proof?

The second debate provided plenty of examples.

The two candidates stood toe-to-toe and clashed over domestic oil production.