Arizona Gov. Jan Brewer's veto of a controversial religious rights bill vehemently opposed by many gay rights groups likely functions as a bookend to her time in office, a tenure that began with a similarly incendiary piece of legislation.

It was five years ago that Brewer, then Arizona's secretary of state, was elevated to the governorship when Janet Napolitano left the state's top job to become head of the Department of Homeland Security. (Arizona has no lieutenant governor so Brewer was next in line.) She seemed unlikely to win a full term in 2010 -- or even win her own party's nomination -- until the nation's most stringent immigration law passed the Arizona legislature and came to Brewer's desk. She signed it and in the process became a Republican hero in the state (and nationally). Her primary opposition disappeared, and she coasted to a victory over Democratic state Attorney General Terry Goddard.

Fast forward to today. Brewer has yet to announce whether she will run for reelection, a decision that, itself, has stirred considerable controversy. She insists she has not met the two-term limit because of her abbreviated first term in office, but that opinion seems to be in the minority in the Arizona political/legal community. (For more on Brewer and the question of term limits, make sure to read Reid Wilson's terrific post in GovBeat.)

The lack of clarity surrounding Brewer's future hasn't stopped a number of Republicans -- eight to be exact -- from getting into the race. And now it seems certain they won't be running against the incumbent.

If any politician understands the political power in signing a controversial measure supported by the most conservative elements of your party, it's Brewer. Had she signed SB 1062, she would have enhanced her position among the most die-hard Republican primary voters -- even while taking a series of body blows from national Democratic (and Republican) leaders. But, unlike five years ago, Brewer chose a different path -- vetoing the legislation and insisting that there is no evidence to support the idea that business owners' rights could be violated by serving gays and lesbians.

Brewer has said she will make a decision on whether to seek reelection sometime around March 1. But, by exercising her veto power of SB 1062 tonight, she effectively has made her future plans known.