State Sen. Leticia Van de Putte, D-San Antonio, is not the first woman to run for lieutenant governor of Texas, not the first Hispanic and not even the first Hispanic woman.

Linda Chavez-Thompson, an established and well-respected labor leader, made the race in 2010. Maria Luisa Alvarado, a political unknown, was the Democratic nominee four years earlier. Like Van de Putte, Chavez-Thompson said at the beginning of her run that she would spend a lot of time south of San Antonio, concentrating on the part of the state that is notable not only for its heavy supply of Hispanic Democrats but also for its remarkably low voter turnout.

One twist on the idea of a demographic wave that might save the Democrats — the notion that there is a growing population of Hispanics who will rescue the party from 20 years of Republican dominance — is that the wave has already reached the shoreline. Texas has enough Democrats to put one in statewide office, according to this theory, but can’t get them to vote.

The evidence is there. In 2008, when the Democratic presidential primary got to Texas, Barack Obama and Hillary Clinton were still fighting for the nomination. That’s unusual; national primaries are almost always settled well before they come to Texas. But this one was a fight. Texas Democrats, goaded by town halls, advertising and news coverage, actually showed up at the polls.

That battle piqued voter interest on the other side too, doubling Republican turnout that year. The difference came later, in the next elections. The new Republicans kept coming to the polls. It turned out to be habit-forming for them. But the Democrats reverted to their customary ennui. In 2008, 2.9 million of them voted — 2.4 million more than in 2006 and two million more than in 2004, the last presidential contest. In 2010, that dropped to 680,548. In 2012, it was down to 590,164.

A new group called Battleground Texas is trying to organize Democrats in the state for future elections, an effort they have estimated will take up to six years. Maybe they ought to advertise on milk cartons, asking for help in finding two million Democrats who went missing after the 2008 primary.

Democrats have few reasons to show up for their March primaries next year. The competition, if there is any, probably will be in local races. Van de Putte and her fellow state Sen. Wendy Davis, D-Fort Worth, who is running for governor, and other statewide candidates are all but nominated, given the absence of other candidates on the ballot.

Their challenge will be to attract voters to the polls in November. The growing Hispanic population, and the idea that those new citizens will vote for Democrats, is not part of the calculation. Even if it happens eventually, it is not going to happen by November 2014.

They have to rely on the voters who are already here, and on their own ability to get those people to show up for an election.

Chavez-Thompson, with her union and organizing experience, could not do it. But she had never been on a ballot, as Van de Putte has. She was not well funded either, and ran, as did most of the statewide candidates, well behind Bill White, the gubernatorial candidate and a former mayor of Houston. White lost badly, drawing only 42.3 percent of the vote against the Republican Gov. Rick Perry. It was worse downstream, where no statewide Democratic candidate broke 38 percent.

Van de Putte might be able to put some money together, especially if she and Davis can capitalize on the excitement displayed during last summer’s filibuster on abortion and women’s health.

Intangibles could help. Van de Putte is more charismatic than her putative running mate, and the race for lieutenant governor could draw some attention. It happens once in a while. The battle between Perry and John Sharp for lieutenant governor in 1998, for instance, was a lot more interesting, and much closer, than the contest for governor between George W. Bush, the Republican, and Garry Mauro, the Democrat.

The synergy might work. This is the first time either party has run two women at the top of a Texas ticket, and Van de Putte opened her campaign with a line designed to hit that note: “Mama isn’t happy. When mama’s not happy, ain’t nobody happy.”