Yes, birth certificates can be forged but right now thats the best thing - IMO.
I agree with you about the purging. A lot of dead people vote. However, you're going to run into the same thing if people are forced to register - they're going to use forged birth certificates. I used to be against a national ID card but if it helps the voting situation and with the problems with illegals and criminals voting I'm beginning to favor it.
Well I'd be in favor of allocating a billion dollars or more to purge all the voter rolls in all the states, and to advertise to the public the need to reregister. Let's start over. Passports would work right away for many who want to reregister, so would military ID's, and for the others we can try Birth Certificates and state issued ID's in combination. It won't be perfect but it would be better than what we have now. Every time I vote, I just give them my name. No ID required. This is absurd.