One of the defining elements of the 2012 presidential campaign is money. Two dozen wealthy Americans have put in at least $1 million each. And one of the biggest donors is Sheldon Adelson, the casino magnate who has almost single-handedly kept Newt Gingrich's campaign afloat.

It's another furious dash to the finish line as delegate-rich Illinois holds its Republican presidential primary Tuesday. Former Massachusetts Gov. Mitt Romney is looking to increase his delegate lead. And he's still searching for that decisive win over former Pennsylvania Sen. Rick Santorum.

Redistricting is forcing a handful of congressional incumbents of the same party to run against each other in primaries. Next Tuesday, two Illinois Republicans square off in a battle of experience versus relative youth, Tea Party versus GOP establishment, and conservative versus conservative.

Mitt Romney and the superPAC that supports him vastly outspent his rivals in Alabama and Mississippi, yet Romney still lost both primaries. This has some political experts wondering: When it comes to TV ads, is there a saturation point?

President Obama's re-election campaign has tried to master the recipe for viral videos with its new 17-minute offering, The Road We've Traveled. This biographical film is directly related to the kinds of movies that campaigns used to make for a party's nominating convention. Its goal is to ultimately reach undecided independent voters.

Although Mitt Romney's stump speech has changed with time, one idea has remained constant from the earliest campaign stops. Romney invariably tells voters that he wants to "restore" America.

President Obama's re-election campaign is releasing a video Thursday that looks back on his first term. The video was directed by Academy Award winner Davis Guggenheim and narrated by actor Tom Hanks. But it isn't anything new: Video tributes to candidates have a long history.

With Illinois holding its GOP presidential primary next Tuesday, NPR's Don Gonyea speaks to voters in and around the iconic American test market of Peoria, asking: Will Illinois embrace Mitt Romney's politics, or follow the South's lead and favor Rick Santorum?

In a gritty contest in the South, the former Pennsylvania senator has won two more primaries to further close in on rival Mitt Romney.

As part of a new campaign, dozens of citizen groups around the country are searching voter registration lists, looking for problems. Critics say the effort is part of a campaign to suppress the votes of minorities, students and others who tend to vote Democratic.