Dec. 26--This wasn't in Laura Miller's job description.

Already consumed with a record-setting bond program, a brand-new comprehensive plan and the small matter of leading the city, Dallas' mayor decided to tackle a daunting task. Ms. Miller took a crash course on coal plants and then took on TXU.

In short order, she recruited a small army of elected officials from across the state and mapped out a game plan for intervening in the complex permitting process for power plants. And while it's certainly within Ms. Miller's rights to care about clean air, this wasn't among her many mayoral responsibilities.

Initially, some political observers questioned why Ms. Miller, who isn't seeking re-election, got involved in an escalating battle over TXU's plans to build 11 coal-fired power plants. But the mayor, who is not known for doing anything halfway, has proved to be a dedicated and effective advocate for air quality.

The energy decisions we make now will affect the air we breathe far into the future. So Ms. Miller's work to protect us from polluting coal plants puts her among the finalists for Texan of the Year.

She has crisscrossed the state, showing up at small-town council meetings to make her case. She has helped elevate the public discourse about pollution and public health. And bringing elected officials who represent millions of Texans to the debate has made this an issue for everyone -- not just the environmentally inclined.

To be sure, Ms. Miller's efforts have been bolstered by the environmental groups that were hard at work on this issue long before she was and by the state lawmakers and business leaders who have since joined the chorus of concerned parties.

But among the many who oppose coal plants, the cheapest but dirtiest option for producing power, Ms. Miller has stood out. Her high profile, her sheer force of personality and her perseverance have helped move the ball forward and have trained a spotlight on air quality issues.

The coal plants proposed by TXU and other utilities threaten to foul our already polluted air and compromise public health. Ms. Miller has done her homework, arguing for cleaner alternatives and outlining the consequences of allowing a coal plant building boom.

With hearings set for early 2007, the battle over energy and clean air is far from finished. But regardless of the outcome, Ms. Miller has fought the good fight.

Coming tomorrow: No. 4DigitalEXTRA Find previous installments of our countdown, as well as reader nominees,

columns by News staffers and nominations by WFAA-TV anchors. DallasNews.com/texanoftheyear