Updated

The 2012 presidential election process began 17 months ago with the first Republican primary debate, and it will fittingly reach its crescendo this month with four debate showdowns.

While President Obama and Republican presidential nominee Mitt Romney will be doing plenty of campaigning and fundraising on the trail during October, the month will be dominated by debates - three between Obama and Romney and one faceoff between their running mates, Vice President Joe Biden and Rep. Paul Ryan.

The first debate between Obama and Romney took place on October 3 at the University of Denver. This swing-state showdown, hosted by Jim Lehrer of PBS, focused on domestic policy, with a heavy emphasis on the struggling economy.

It will be Biden and Ryan that meet up next with a wide-ranging debate at Centre College in Danville, Ky. Given Biden's colorful style and Ryan's reputation as a policy wonk, moderator Martha Raddatz of ABC News will have her work cut out for her to keep to the tight time limits set for the contest. The Oct. 11 debate will be the only meeting of the running mates.

The following week will see a town-hall style debate in which Obama and Romney take questions from audience members at Hofstra University on New York's Long Island. The audience members will be undecided voters identified by the Gallup polling firm and invited to the campus to take part in the Oct. 16 debate. It's a format that Democrats believe will play to the president's abilities to relate to voter concerns. Republicans, meanwhile, are counting on the audience members to provide tough questions for the vulnerable incumbent, perhaps tougher than come from media moderators.

Depending on how the first three debates go, the stakes could be very high, indeed, when the presidential candidates roll in to Boca Raton, Fla., for the final contest on Oct. 22, hosted by Lynn University. That event, moderated by Bob Scheiffer of CBS News, is scheduled to focus on foreign policy. But with Election Day just a bit more than two days away, the conversation could broaden as the candidates try to land their closing shots.

While Obama, Romney, Biden and Ryan are duking it out, candidates in a half dozen competitive gubernatorial races and a dozen competitive Senate races will also continue to face off. With Republicans just four seats away from taking control of the Senate, these contests, especially in swing states like Virginia, Wisconsin and Florida will get national-lever scrutiny.

October will also be the month when the television ad wars intensify, and not just from the campaigns and parties. Outside groups, including political action committees and labor unions, have been amassing money for a late push in the presidential race as well as state-level contests.

Something else to count on this month: October surprises. Campaigns and political operatives often keep some of the best bits of dirt for a late strike. The final week of October will be prime time for operatives looking to launch a scandal story soon enough for voters to hear about, but late enough that the target doesn't have enough time to explain it away.