One of the biggest debates this year has been the new voter ID laws that have been passed in several important states, primarily by strong Republican majorities. Those who oppose these laws point out that there is little to no evidence of voter fraud being a problem, and definitely no evidence that it is an epidemic problem requiring legislation that very clearly disenfranchises large numbers of voters.
Those who support such measures say that voter fraud is a huge problem, and that we don't know about it because there's no way to find out when it's happening. It's very convenient that we are in the midst of a crisis of voter fraud, which we can't track and can't predict, but that will be completely stopped by requiring voters to show a photo ID. And, if those laws prevent millions of people across the country from voting due to a lack of such ID, well, then that's just an unfortunate side-effect to maintaining the validity of our voting system.
But John Stewart takes the Republicans to task in his latest Daily Show by pointing out that even Republicans can't seem to find evidence that would suggest these laws are necessary. Furthermore, it's been shown that while states with voter ID laws have allowed for ways for voters to get free ID's from the state, they require a photo ID to obtain, making them superfluous.