Many people were simply interested in understanding the meaning of particular terms. Governor Palin called Senator McCain a "maverick" several times, sending many viewers to Google to query definition of maverick, what is a maverick, and define:maverick.
When Biden mentioned that the "theocracy controls the security apparatus" in Iran, users searched for the meaning of theocracy — as they did when he spoke of the windfall profits tax.
Getting these definitions got a bit tougher when the candidates couldn't even agree on pronunciation. Discussion about a certain type of energy caused a flurry of queries: nucular vs nuclear, nuclear pronunciation, palin nucular, and even nukular. And when Senator Biden talked about the "7,000 madrasses built along [the Pakistani-Afghan] border", the queries ranged from madrass, madrases, madrasa, and even madras, a major city in India that's most definitely not on the Pakistani-Afghan border.
Governor Palin's claim that "Israel is in jeopardy of course when we're dealing with Ahmadinejad as a leader of Iran" led viewers to try to learn more about this leader even if they could not spell his name. They searched for [Achmadinijad], [Akmadinijad], [Akmadinajad], and the correct Ahmadinejad. Some did not even try, instead looking for [president Iran] and [Iran leader]. The Governor also referred to General McKiernan, the U.S. military leader in Afghanistan, as "McClellan", sending viewers in search of McClellan, general in Afghanistan, General McClellan Afghanistan, and general Afghanistan surge. Some searchers eventually did find the correct general, but not that many.
Historical references abounded. When Senator Biden claimed "This is the most important election you will ever, ever have voted in, any of you, since 1932", some people wanted to know what it was about the 1932 presidential campaign between Herbert Hoover and Franklin Roosevelt that was so special. And twice as many them wanted to know about that "shining city on a hill", a phrase from Ronald Reagan's farewell address that was originally coined in 1630 by John Winthrop.
When Senator Biden offered a civics lesson ("Article I of the Constitution defines the role of the vice president of the United States, that's the Executive Branch") many people checked, and learned that Article I of the Constitution describes the legislative branch of the U.S. government. The executive branch is described in Article II. Others just searched directly for the role of vice president and vice president duties.
People searched on clean coal and took a look at Senator Biden's position (as the candidate asked them to) with queries like Biden clean coal.
These are some of the more interesting queries, but which were the most popular ones? Among the candidates, Senator Biden was a big winner. Searches on him soared more than 70-fold, compared to a week earlier. Governor Palin, much more of a search favorite in the weeks leading up to the debate, only saw a 6x jump, but her volume outpaced Senator Biden's.
Register to vote] was also quite popular; we even have a special site for that.
The Commission on Presidential Debates, which hosts the debates, has stated its objective as providing "the best possible information to viewers and listeners". From Google's perspective — the little search box on viewers' and listeners' computers and mobile phones — the vice presidential debate did a pretty darn good job.
We'll give you an update on tomorrow night's debate later this week. In the meantime, keep an eye on the most recent queries yourself on Google Hot Trends; they change frequently and will start to reflect the debate's talking points soon after it finishes.