They consider renters to be non-residents right up there with the homeless. Both are considered to have no actual roots in a specific district. It doesn't matter if you have lived in the same rental property for 30 years. You are considered to be a "transient". They would like to drop EVERYONE with an address that has a second number on it that looks like an apartment number. People in condos get targeted this way too.
Then there's the people who lost their homes to foreclosure. Republicans claim these people are no longer residents either and therefore should be dropped from the list of registered voters. Some states send out voter verification forms that look like junk mail and if they get no reply, they drop you. Those are specifically not forwarded to a new address but returned for instant purge.
I'm waiting for them to come up with a fund raising letter with Romney's face plastered on it and by the way, you toss it, you're purged,...have a nice day....