Typical politician stuff.
Brewer only signed Constitutional Carry and SB1070 because she spent all her political capital on the tax increases and needed to regain conservative support. Constitutional Carry bought votes and 1070 reframed the debate in her favor, giving her the primary and general election on a silver platter. Brilliant.
She doesn't have any big political problems this year, so now she feels she doesn't need libertarian gun owners' votes badly enough to risk looking bad after Tucson.
Funny thing is right now the same thing is happening in Illinois. Political leaders are about to throw a CCW bone to keep in office after supporting gay marriage and ending the death penalty.
Brewer will support self defense rights again when it is in her best political interest.