We already are preventing voter fraud before it happens. The I.D.'s required under these new laws will do nothing to add integrity to our system.
Here's a study that's been done on the topic.
http://brennan.3cdn.net/c176576c0065..._gxm6ib0hl.pdf
This is what the author concludes:
These voter I.D. laws are an idea from the ALEC which is a conservative think tank/lobbying group. They also brought us the castle and stand your ground laws. In 2012 they disbanded their task force which dealt with these initiatives because they were losing gobs of money from large corporations who didn't want anything to do with this stuff.