Every two years, that old bogeyman ACORN and stories of voter registration fraud by its employees pop up to stir the Republican base. Every year, the stories turn out to be of minor consequence. Generally lost are the explanations of how the Mickey Mouse voter registration cards are neither so wild nor as dangerous as depicted.
Paid signature gatherers sometimes cheat. They are usually caught. A non-existent voter can't vote. The fraud is as much against the organization that pays the canvasser as against the system. Etc.
None of this will soothe the savage GOP breasts, any more than the wealth of explanatory journalism dissuades them from making ACORN the villain in the housing collapse.
Just the same, Josh Marshall has a useful essay and links on the voter registration issue.
It's simple, really. Democrats want as many people to vote as possible. Republicans want fewer people to vote, preferably only their kind of people. Sample question: Should a person who lacks a permanent residence (perhaps his home has just been foreclosed) be allowed to vote for president?