Foreign policy. The lone vice presidential debate will have nine, 10-minute sections and include both domestic and foreign policy. The latter area is where Ryan and Biden are clearly mismatched.

Romney and Ryan have stepped up their criticism of Obama’s foreign policy after last month’s attacks on U.S. diplomatic missions in Libya and Egypt, and the administration is facing criticism over how long it took to acknowledge the attack in Libya was a terrorist act.

Still, Biden should have an upper hand as the former chairman of the U.S. Senate Committee on Foreign Relations and as someone who played a key role in the administration’s withdrawal from Iraq. Ryan has little foreign policy experience.

Social issues. The election is about the economy, but the Obama campaign would love to see a discussion on social issues such as abortion. That could help reverse some ominous signs it has seen lately about women voters: A Pew poll released Monday showed that Romney had closed an 18-percentage-point gap among women.

Ryan has been among the most hard-line opponents of abortion rights in Congress, including co-sponsoring a “personhood” amendment that would have made abortions illegal in cases of rape.

Romney earlier this week suggested he had no plans to pursue any abortion restrictions, prompting questions to Ryan about that Wednesday as he left St. Petersburg after two days of debate prep. “Our position’s consistent and hasn’t changed,” Ryan said.

Incidentally, this is the first time that both tickets include a Catholic.

And it may not even be their last debate. If Obama wins re-election, both Biden and Ryan could be leading presidential contenders in 2016.