but it sure is easy for illegals to do so.

http://news.yahoo.com/s/ap/20070622/ap_on_fe_st/odd_vote_dog_1;_ylt=AmX3O8Tj08zIZLl7iwMSpUtkM3wV

Yet, politicians refuse to require a real ID in order to cast a vote.

Umm...this is about mail in votes. Mail-in votes are easy to forge.

What would an ID do about that?

Actually its about the piss poor system used to register voters. It just shows anyone, or anything can obtain a voter registration card, and a utility bill. The only two items needed to cast a ballot in person. An ID check would prevent that from happening.
And that scares the living shit out of politicians.