To be honest I'm with Jim Robinson when I say I'd rather deal with illegal immgiration over a national ID/domestic passport. But conservatives have been suckered into going along, with "illegal immigration" becoming the stalking horse used to sneak it in.
Why does it have to be a "one or the other" proposition? Again, the Real ID Act would be completely unessessary if we cut off all illegal alien welfare, rescind the law the states that any person born in the U.S. automatically becomes a U.S. citizen, fine employers for hiring illegal aliens, and secure our borders to the best of our ability.