Gingrich, Romney and Paul all appear to have a shot at the nomination based on polls in the early states: Iowa on Jan. 3, New Hampshire on Jan. 10, South Carolina on Jan. 21 and Florida on Jan. 31. These four states will shape which two or three candidates are likely to survive into the grueling contests that follow. As part of its Election 2012 coverage, AARP will be keeping track of the delegate count.

Money is king. What's come to be known as the political-industrial complex will raise and spend at least $8 billion in the 2012 campaign, experts say. Obama has already raised at least $86 million for his re-election campaign, and his campaign has quietly set a fund-raising target of $1 billion. The Republican candidates combined have raised about as much as Obama. Much of this money will be poured into television ads, which are likely to start out positive in tone and gradually go negative. (Attack ads, history tells us, work.)

Individual contributions to a presidential candidate are limited to $5,000 ($2,500 for the primaries and $2,500 for the general election). But the Supreme Court's 2010 ruling in Citizens United v. Federal Election Commission allows unlimited amounts of money to flow into the political process. The ruling, undoing key post-Watergate campaign finance reforms, allows corporations, nonprofit organizations (such as AARP and the National Rifle Association), labor unions and wealthy individuals to spend whatever they want on political advertising and activities, as long as they do not coordinate with candidates or their campaigns.

So-called "Super PACs" (political action committees) have sprung up to haul in multimillion-dollar contributions. Casino mogul Sheldon Adelson, for example, reportedly is planning to give a jaw-dropping $20 million to a Super PAC that's backing Gingrich. Adelson, however, has denied that he's made a specific commitment. Other groups hide behind IRS rules as tax-exempt charities and do not disclose their donors. One example is the 60 Plus Association, a nonprofit organization that's' been described by PR Watch as "a corporate assault in 'good-for-seniors' clothing." It spent $7 million in the 2010 elections, most of it on political attack ads.

"Voters can expect a steady barrage of ads run by unfamiliar groups with patriotic-but-generic names," says Sheila Krumholz, executive director of the Center for Responsive Politics, a watchdog group. "Unfortunately ... more and more of their donations come from secret sources."

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