Had she not followed her grandfather's instructions, Guerra, now a Democratic strategist, might have gone down a different path. Now 31, she recalls how voting in that local election -- though she cannot remember what was on the ballot -- started her on a journey that has included leading the bruising but successful recent campaigns of two state senators and a state representative.
Of her grandfather's instructions, she said, "I just remember him yelling names at me, he was a couple of booths down." She remembers thinking, "This is embarrassing." Her former employers say Guerra is a force behind the scenes, and more than a mere up-and-comer for the state's beleaguered Democratic Party. She is viewed by some in the party as a rare weapon for progressives in a conservative stronghold.
Part of Guerra's drive comes from a lack of patience with Democrats who think the party's time will eventually come.
"We've been in this holding pattern for so long, like we have to wait until 'this' year before Texas turns blue," she said. "I just think, I am not getting any younger. I don't want to wait for it to happen. I just want to make it happen."
The second of five children, Guerra was raised by her mother and her grandparents.
Her mother held a number of odd jobs, including part-time work at an Army surplus store, before landing a job at the state's Health and Human Services Commission. She eventually joined the state employee's union and became enthralled with Democratic politics.
Guerra, a graduate of Texas A&M University, said her mother's passion, along with lessons in elections and politics from her grandparents, steered her toward her current path.
She became a field worker for the Texas Democratic Party, and then eventually joined state Rep. Chris Turner, D-Grand Prairie, when he was working for former U.S. Rep. Chet Edwards. She became a consultant for Turner's campaign when he decided to run for the Texas House.
Her latest victory came this month, when she helped propel state Sen. Sylvia Garcia, D-Houston, to victory. Garcia defeated state Rep. Carol Alvarado, a fellow Houston Democrat, in a special election that began late last fall and started with a field of eight candidates.
"We were both interviewing each other," Garcia said. "I was looking for the right manager, and I think she was looking for the right candidate, and I think it was just the right match."
"I saw her handle more than one problematic issue on the campaign to where you saw she was chiquita, pero picosa," Garcia said, using a phrase meaning small but spicy. (Guerra is barely 5 feet tall in her signature cowboy boots.) "You saw where she was there to protect me as a candidate, there to protect our campaign."
Guerra joined Garcia's team a week after leaving the victorious campaign of state Sen. Wendy Davis, D-Fort Worth, who survived a challenge from former state Rep. Mark Shelton, R-Fort Worth, in the most expensive state Senate race of 2012.
Davis said Guerra was one of several people the senator interviewed, and though she lacked experience in a race of similar size and expense, Davis was soon won over.
"Despite how unassuming she can be, she was not at all afraid to ask for the job and assure me with tremendous confidence that she knew she was capable of doing it," she said. "It's a pretty rare quality for a person of her age, and for a woman, and probably even more rare for a woman of that age who is a Latina. But she has a tremendous self-confidence, and I think that's one of the things that keeps her very happy to be behind the scenes."
Davis came to believe her decision when she saw how Guerra commanded her field workers.
"I would go in to her office and say, 'So what are we doing with the field?' because I just wouldn't have a clue," Davis said. "And she would have a list of well-focused ideas and plans already set in place that she just does because she knows how to do it."
Bryan Eppstein, a Republican consultant who served as an adviser to Shelton, said he had not met Guerra but would "shake her hand" if he did.
"I think you have to give credit to the other side when they win an election," he said.
He pointed out that Davis raised $2 million more than his client and did not have to win a primary election. Eppstein said his research showed that about $1.4 million of the $2 million edge came in the campaign's final weeks.
"They ran a very intensive campaign on a strong get-out-the-vote strategy," he said. "And they spent significantly more money, and they got more votes, so congratulations to them."
While Guerra worked on Turner's successful 2008 and 2012 House campaigns, her tenure with him also includes his failed 2010 bid for re-election, which Turner said had nothing to do with Guerra's efforts.
"I was treading water in a Republican-leaning district, and when you're treading water and you have a tidal wave wash over you, there's nothing much you can do," he said.
Asked what advice she would give Guerra, Davis suggested a repeat of past success.
"This is purely selfish on my part, because my hope is that she'll be managing my next campaign," she said.
Turner was direct. "I think she's going to have a lot of options, and the only stipulation I have for Terrysa is that she absolutely cannot leave Texas," he said. "Under any circumstances, ever."
Guerra smiled when she heard the praise, but she would not conclude that the party was close to regaining its momentum. As in every party, she said, there are failures.
"To be blunt and honest, I think a lot of people need a good kick," she said. "There is drama in every party, people who don't like each other and the egos, and it's always going to be there and it's going to be our downfall."
There is a way to transform the status quo, she said. "You change the people in charge, you change the perception," she said. "You figure out how they are going to be useful. If they're not, you figure out how to deal with that."
Guerra is taking time to determine what her next challenge will be. "Texas is a big challenge of its own," she said. "And frankly, I love it too much, and I am way too loyal."
"And," she added, "there is unfinished business here."
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