[...] the Democratic candidate for Texas governor is in a soldier's backyard in an especially conservative corner of the state that she has no hope of carrying, addressing 30 campaign volunteers as they slap at stinging fire ants. The state senator dares critics to count her out, but her well-funded and popular Republican opponent, state Attorney General Greg Abbott, looks so unstoppable that the question now looming over the race is whether defeat will reduce her to a spent political force. Win or lose, Texas Democrats insist, Davis will remain atop the party alongside rising state stars such as Julian Castro, who stepped down as San Antonio mayor to become the nation's housing secretary and has been mentioned as a possible vice presidential nominee in 2016. Since Davis is giving up her Fort Worth-based Senate seat, she could take her national profile to a political think tank or a job as a television pundit. Since Richards' day, most Democratic gubernatorial candidates have disappeared from the political landscape after defeat. [...] her political power peaked with the filibuster. [...] she has struggled to define herself beyond abortion rights and spent most of the campaign reacting to Abbott rather than honing her own image.