Republic columnist Bob Robb has this scathing assessment of the Napolitano's legacy as Governor of Arizona.
Napolitano dominated her political party more than any other state politician in the modern era. At the zenith of her power, in 2006 and 2007, she defined the center of Arizona politics. Yet, today, there’s not a trace of her influence or legacy. It’s as though she never was governor.
I think that's almost right. However, Napolitano demanded one policy change, fought for that change and forced the Legislature to adopt that change. Opponents then sued to unwind that change...and it went all the way to the US Supreme Court and the court upheld that policy. Now that once controversial policy has become part of the conventional solution and is being adopted throughout the country.
That policy is the Employer Sanctions law. Most Arizonans assume that Napolitano was forced to support the Employer Sanctions law because the conservative legislature had pushed it through and if she vetoed the bill, Russell Pierce would have taken the policy to the ballot.
That's not how it unfolded. It was state Democrats who advocated for employer sanctions as a way to split the "chamber" wing of the Republican Party from the "Immigration" wing of the Republican Party. Napolitano vetoed an immigration bill that lacked employer sanctions and she used her State of the State address to demand that the Legislature send her an employer sanctions bill.
The issue was so powerful and resonated so much with voters that the "Chamber" wing of the Republican Party caved to the pressure and gave Napolitano what she wanted.
I have a full chronology here. (The most interesting part of the story is the point at which the Democratic caucus realized that Napolitano wasn't demanding sanctions in order to split the Republican caucus....she actually wanted a sanctions bill. Legislative Democrats were then forced to beg her to veto the bill after loudly calling for its passage.)