"conducting voter mobilization drives in an attempt to persuade new or apathetic voters to turn out in support of their causes — mostly Democratic — on Nov. 2."
Why did republicans not do the same?
you are missing the point - these are not the registrations of real people flocking to Dem voting centers and filing out their forms. these are forms filled out by Dem operatives in the 527s going through motor voters lists and phone books and welfare rolls and anything else they can get their hands on to cross reference names and addresses of living (or otherwise) human beings who aren't on the rolls.
come election night, just before the polls close, in polling places in Dem strongholds - the votes of these now registered people who don't show up, have their votes cast for them.
We are... except that our electorate is not quite so apathetic.
There are voter drives going on in churches and then there's Project Joshua, a voter registration drive organized by civic-minded homeschooling teens, loosely affliliated by Home School Legal Defense Association. If homeschoolers, who have an incredibly high voting percentage, can convince other evangelicals to vote, our numbers will receive a much needed boost.
Maybe the Republicans have scrupples whereas the Dems don't?