It's called "street money" and it is a practice that most big city Democratic machines use to scare up votes on election day. The actual mechanics vary from city to city but it usually involves hundreds of people getting thousands of dollars in walking around money that they can use at their discretion to get people to the polls.
The prospects for fraud are great, of course. And there are few cities where that is truer than Philadelphia. Obama turned up his nose at supplying this street money to the Philadelphia Democrats during the primary and got clobbered by Clinton. John Fund in the Wall Street Journal (subscription only) explains why he has changed his mind for the general election:
Republicans will be watching what happens in Pennsylvania on election day very carefully. Of course, they will be accused of "intimidation" for doing so but better that than have the election stolen out from under you.
Mr. Brady went on to say that by his calculations, Mr. Obama needs a massive Philadelphia win in order to carry the state's 21 electoral votes because he doesn't have the support in central and western Pennsylvania that Al Gore or John Kerry enjoyed. "I think we're going to need that because of the middle part of the state. McCain plays right in there," he said.
Of course, the massive size of Democratic margins in Philadelphia (often exceeding half a million votes) has regularly been a subject of controversy. A key state legislative victory by Democrats was thrown out by a federal judge a few years back due to massive vote fraud. The rolls of city voters have for years contained more registrations than the city contains people over 18, according to Census data. These excess registrations represent an open invitation to turn "street money" into phantom votes if a sufficient number of the living kind can't be drummed up.
For all the hype about his successful Internet campaign, it appears Mr. Obama has reluctantly decided that the "old politics" has it uses after all and must now be embraced.
Hat Tip: Ed Lasky