After finishing a dismal fifth — out of six candidates — in the GOP's Iowa caucuses despite spending $4.5 million on TV ads, Texas Gov. Rick Perry said he was heading home to "reassess" his campaign. Since "reassess" usually means "snuff out," everyone from party strategists to Perry aides figured that meant he was going to drop out. But Perry "shocked" the political world on Wednesday, tweeting that he was moving on to South Carolina's Jan. 21 primary. He also says he'll participate in two weekend debates in New Hampshire ahead of its Jan. 10 primary. What's keeping Perry in the race? Here are four theories:

1. The picture is brighter in South Carolina
The Iowa results painted a "dark portrait" of Perry's chances, says Richard Dunham at the Houston Chronicle, but there were "some rays of hope." Perry got solid support from blue-collar Republicans, who are plentiful in both South Carolina and Florida. Perry also appealed to Iowa's evangelical Christians, and South Carolina is "a hot-bed of Religious Right influence." Perry also suggested to reporters that Democrats had infiltrated Iowa's caucuses, says Jason Embry at the Austin American-Statesman, and he says he looks forward to campaigning before "real Republicans" in South Carolina.

2. Perry is in denial
"One of my favorite lines from [NBC sitcom] 'The Office,'" says Christian Heinze at The Hill, "is when Michael Scott proudly and hilariously says: 'I'm not leaving. I'm going nowhere.'" That's essentially what Rick Perry is saying now. "He's staying in the race, but doesn't seem to realize he's toast, and instead of seeming resilient and courageous, it just seems stubborn and unrealistic."

3. Perry's campaign war chest still gives him an edge
"Perry still has some money in the bank," say Paul West and Mark Z. Barabak at the Los Angeles Times. So he has no reason not to give his "newly tailored message" two more weeks to win over social conservatives in South Carolina. Perry's strongest Iowa demographic was voters influenced by TV ads, 19 percent of whom chose Perry, says the Houston Chronicle's Dunham. With way more cash than Newt Gingrich and Rick Santorum, Perry could, in theory, buy enough ads to "vault him over other conservatives."

4. Sometimes "reassess" just means reassess
The conventional wisdom is that when a candidate says "reassess," it's "merely a prelude to formal withdrawal," say Emily Schultheis and Jonathan Martin at Politico. But Perry did what he said. He considered input from advisers urging him to give up and from "Texas backers... urging him to go forward." Perry was hoping for a revitalizing third-place finish in Iowa, but needed time to absorb the meaning of a fifth-place finish, says Dave Montgomery in the Fort Worth Star-Telegram. He did, and decided his next step should be tweeting a picture of him in a jogging suit, with the words, "Here we come, South Carolina!"