For instance, voters in three urban state senate districts — overwhelmingly black districts in Dallas and Houston, and a white liberal enclave of Austin — will choose 21 convention delegates between them.
But because of low Latino turnout for Democrats in the 2004 and 2006 elections, some state senate districts choose as few as two delegates each.
"Clinton could win the statewide vote, but she could still just break even or end up behind in the delegate count," said Martin Frost, a former congressman from Dallas who is neutral in the presidential race. "The press is playing attention to who wins the delegates, so that will be important."
Texas' odd system of allocating delegates has flummoxed the Clinton campaign. Clinton told reporters over the weekend that her aides were still struggling to understand how the state operates.
"I've got people trying to understand it as we speak," she said. "Grown men are crying as we speak. I had no idea it was so bizarre."
Asked by ABC News how the Clinton campaign would define success in Texas, Clinton communications director Howard Wolfson said he wasn't sure.
"I think all of you will be looking at a lot of different data points to determine who wins the night," Wolfson said.
"I think obviously, the delegate counts in this state is one of them, but I'm not going to presume to tell ABC News how to determine the outcome from a rhetorical standpoint. But I think we're going to do very, very well."
A CNN poll released this week had the race statistically tied, with Clinton up 50-48 over Obama.
Clinton is focusing her efforts on Texas' Hispanic communities.
She reminds crowds of her work in South Texas on behalf of George McGovern's 1972 presidential campaign, and she's pumping resources into the Democratic-leaning counties that line the border with Mexico, and setting up field offices in Hispanic neighborhoods in the big cities.
"The Latino voter, from Dallas all the way to the Rio Grande Valley, they've heard they're going to be the difference, and they're going to show up for her," said Marc Campos, a veteran Houston-based Latino Democratic consultant who is not aligned in the presidential race.
"There's a historical link between the Clintons and the community — they've been here, and everybody knows their history," Campos said. "The Latino community feels, they've inspired us, they think we're important for them. They don't want to be the ones who end her political career."
Independent observers expect Latinos to comprise roughly one-third of Democratic primary voters — though the Clinton campaign hopes to nudge that figure above 40 percent.
Exit poll data from 2004 suggests that the Latino population is roughly similar in socioeconomic status to Latino voters in other Southern and Western states, with more than 70 percent lacking college degrees and a similar portion earning less than $50,000 a year.
If Texas Latinos vote as they have in other states, Clinton could expect to receive about two-thirds of the Latino vote.
But that edge could be essentially nullified by the African-American vote, which is expected to make up one-fourth of the primary vote, and is energized on behalf of Obama. In other states, black voters have been favoring Obama by as much as 80 and 90 percent.
That leaves the battleground to the state's white voters, a diverse group that could represent as much as 40 percent of the voters on March 4.