How Unknown Candidates Sometimes Win Elections

South Carolina Senate candidate Alvin Greene Mary Ann Chastain / AP

There are unknown political candidates, and then there's Alvin Greene, the winner of Tuesday's Democratic U.S. primary in South Carolina. Local party leaders first heard about Greene, a 32-year-old unemployed U.S. Army veteran, when he showed up at their headquarters in March with a $10,400 check and told them he wanted to run for Senate. After he paid the filing fee, Greene disappeared. He missed the state party's convention, raised no money, and did no campaigning that Democratic leaders knew of.

Yet somehow, in a stunning development, he got more than 100,000 votes in Tuesday's primary, winning 59 percent of the vote and the right to run against Sen. Jim DeMint this fall. All of which begs the question, has a candidate like Greene ever won before?

Voters casting their lot in favor of someone they've never heard of is actually fairly common in low-key races, political scientists say, and the race to compete against a strong and well-funded Republican incumbent like DeMint qualifies as low-key. It's also not as rare as one might think for obscure candidates to spend little to no money on their campaigns. Casino pit boss Robert Tingle spent so little in his doomed 2008 challenge to Rhode Island Sen. Jack Reed that he's not even listed in the Federal Election Commission's campaign-finance database. "Almost every year there are one or two Senate challengers who raise no money," says Alan Abramowitz, professor of political science at Emory University.

It's also worth noting that Greene's opponent in South Carolina, a judge and former state legislator named Vic Rawl, polled poorly among South Carolina Democrats last month: only 4 percent had a favorable opinion of him, while 82 percent were unsure, according to a May survey by Public Policy Polling. That's a strong indication that many S.C. Democrats simply didn't know who Rawl was either.

If that's the case, then it's anybody's guess how the 100,000 or so folks who voted for Greene made their decision. Abramowitz said race can sometimes tip the balance in elections where voters don't know much about the candidates. Indeed, Greene is black, Rawl is white, and there are many African-American voters among South Carolina Democrats. But it's not clear that voters knew even that much about these two candidates when they stepped into the booth, and their photos were not on the ballot. We can also throw out the possibility that Greene got the votes because the ballot listed him as a veteran; candidates' occupations are not listed on the ballot in South Carolina either.

More likely, voters were simply choosing based on an immediate reaction to the names they saw. Name recognition matters at the polls, after all. Look no further than the electoral success of Texas Democrat Gene Kelly, who shares a name with the late actor and who received more than 9 million votes in 14 elections without running much of a campaign. Greene may not have had that sort of name recognition, but his name was listed above Rawl's on the ballot. "It is pretty well established that being first helps," says Gary Jacobsen, political science professor at the University of California, San Diego.

Or perhaps voters chose based on their reaction to the names, which appeared as "Alvin M. Greene" and "Vic Rawl." Maybe "Senator Greene" has a nicer ring than "Senator Rawl"?

For Greene, at least, relative obscurity is no longer his biggest problem. He was arrested in November for allegedly showing obscene Internet photos to a University of South Carolina student, according to the Associated Press. ABCNews says he was kicked out of the Army, too. Now three months after Greene gave them that $10,400 check, South Carolina Democrats have asked him to withdraw from the race.