Rick Santorum was the longest of long shots when, five years after losing his bid for reelection to the Senate by 18 points, he spent much of 2011 campaigning for president in three early-primary states. But he campaigned longer and harder - albeit with less media attention, money, and staff - than any other Republican candidate. By the time Santorum barely won Iowa (as we belatedly learned), he had held nearly 400 town-hall meetings.
The rise of Santorum can be attributed to several key factors:
Media coverage: Santorum's universally unforeseen sweep of the contests in Minnesota, Missouri, and Colorado last week won him enormous attention on broadcast and cable news across the country.
A campaign that had struggled to raise $1 million over three months in 2011 raised more than $2 million in the 72 hours that followed that romp.
Electability: Santorum is the most electable conservative remaining in the race.
Despite Newt Gingrich's high name recognition and his history as a leader of the conservative movement, his baggage has proven insurmountable. Gingrich's only win, in South Carolina, came on the heels of two dynamic but unrepeatable debate performances, and he has been unable to unite social conservatives with fiscally conservative tea-party voters.
Santorum has solid, long-standing support among social conservatives, and recent polling shows he is winning more tea-party support. It helps that he opposed the federal bailouts that Gingrich and Mitt Romney supported.
Absence of gaffes: This campaign has seen several national front-runners: Donald Trump, Michele Bachmann, Rick Perry, Herman Cain, Newt Gingrich. But all of them were unable to sustain a burst of support in the harsh glare of national media scrutiny.
Santorum's campaign had been left for dead many times, but it conserved its resources, developed a unique strategy, and let its workhorse drive it while committing very few gaffes. When Santorum has been given an opportunity - as he was when Romney's campaign foolishly underestimated the potential impact of a Santorum sweep last week - he has seized it.
Solid debates: It's hard to overstate the importance of the televised debates in this campaign. While nearly every Republican candidate has had a bad debate or a cringe-inducing moment, Santorum's performances have been consistently solid, leaving audiences with the impression that he is intelligent, confident, and experienced. His tactic of lumping Romney and Gingrich together on such issues as bailouts and an individual health-insurance mandate has been particularly effective in setting him apart.