San Antonio (CNN) One of the clearest indications of the weakness of Donald Trump's candidacy is how far he has lagged behind past Republican nominees in red states. There is Arizona, where Hillary Clinton is currently making a real play, as well as Utah -- where Mormons have reacted with revulsion to his campaign.

Perhaps most striking is the close race in reliably red Texas, where no Democrat has won the presidential race since 1976.

Democrats have long eyed the staunchly conservative state with swiftly changing demographics as a future battleground. The fact that Clinton is only behind Trump by single digits here is stoking excitement that Texas could shift from a solid red state to a purple one much earlier than anyone thought. A University of Houston poll recently showed Trump with 41%, to Clinton's 38% in a four-way race.

But close observers of Texas politics say they are all but certain that Trump will ultimately win the state's 38 electoral votes on November 8. And they question whether the race is close because voters are tilting leftward, or simply reacting to Trump.

Many voters here point out that they live among immigrants, and embrace that aspect of America's culture, while understanding the complexity of immigration policy. Trump's rhetoric has turned off voters of many different races and nationalities. That is a major reason why he is trailing so far behind Clinton in states like Colorado; why states like Arizona look competitive; and why Trump's path to 270 electoral votes has narrowed so dramatically.

But there has been no real push by the Clinton campaign to capture Texas, and no major mobilization of Democratic voters on the ground.

"I think this is the year Texas could have gone blue," said Matt Angle, director of the Lone Star Project, a political action committee aligned with Democrats. "But you don't win a state like Texas unless there's a real, aggressive and engaged campaign to win it."

Still, many here believe Clinton could draw a greater share of the vote than even Obama did in 2008, when he won nearly 44% of the vote to Republican nominee John McCain's 55.5%.

Looking to appear on offense, the Clinton campaign placed a six-figure ad buy in Texas this month highlighting the endorsement of her campaign by the Dallas Morning News -- the first time the paper backed a Democrat since 1940. But the low-dollar investment in an exorbitantly expensive state was largely a symbolic gesture.

A strong Clinton showing on Nov. 8 "could reinforce the argument that Texas doesn't have to wait for demographics," Angle said. "One of the biggest myths about Texas is that Democrats always get stomped on here." The reality, he said, "is just that we seldom have the resources to compete statewide."

Democrats who want to see the national party invest more heavily in this state are eager to see what the Trump effect will be in the 23rd Congressional District, a swing district stretching from the San Antonio suburbs to El Paso that is more than 70% Hispanic.

Freshman Rep. Will Hurd is in a fierce race to defend his seat against former congressman Pete Gallego. Democrats believe that reclaiming that district would show that if they put resources behind a strong Democratic candidate, they can win.

James Henson, director of the Texas Politics Project at the University of Texas at Austin, is wary of reading too much into this year's statewide poll numbers as signs of a seismic shift in Texas. In interviews here, many Republican voters said they simply loathed both Trump and Clinton -- and were particularly offended by Trump's rhetoric on immigrants.

"I would have voted Republican... Normally this is a Republican state, but Trump has pretty much said a lot of things to piss everybody off," said Jerry Carrasco, a 45-year-old independent from San Antonio, who voted for both George W. Bush and Barack Obama.

"He sounds racist to everybody. He has to realize that we're all immigrants -- I mean if you're not Native American -- you're not a true American. He forgot that," said Carrasco, whose family immigrated to Texas from Mexico in the 1800s. "If he's going to run for president, he needs to be more respectful. He sounds like an idiot at times."

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Carrasco said he and his colleagues laugh about the sheer impossibility of Trump's proposal to build a wall: "I've worked out there in South Texas and it's difficult. It's very harsh terrain and the way the Rio Grande always floods, the soily roads. It's not going to happen."

"The border -- they're never going to stop that," Carrasco added. "They're going to be crossing no matter what. If you put a fence up they're just going to find a way to get around it."

The Trump effect could make the closeness in Texas a one-time phenomenon. Past efforts to increase the share of the Latino vote from 17% of the electorate have largely been unsuccessful, particularly those by the group known as Battleground Texas and the Wendy Davis gubernatorial campaign in 2014.

"As long as I have been following politics, Democrats have been saying 'We're going to go out, we're going to mobilize Hispanics this time, and we're going to take back the state,'" said Henson. "In fact it's gotten worse from the Democrats' perspective," he said, pointing out that there are currently no statewide Democratic officeholders. "So it's hard not to look at (this year's poll numbers) without a certain degree of skepticism."

Latinos backing Republicans

Latinos in Texas tend to be less liberal than in other parts of the country, and have comfortably voted for Republican candidates, including former Texas Gov. George W. Bush and current Gov. Greg Abbott. (In the 2014 midterm election, GOP Sen. John Cornyn won 48% of the Latino vote; while Abbott won 44% of the Latino vote, according to some exit polls).

There are fewer immigrants and more natural born citizens within the Texas Latino population than nationally. And there's a much higher rate of home ownership among Latinos in Texas than nationally, said Henson.

Those factors together make Texas Latinos more conservative than most people would assume based on voting trends in other parts of the country. "We know from survey research now over a few decades that the farther you get from the immigrant experience, the more your views shift in a more conservative direction," said Henson.

Census data shows that Latinos now make up 38.8% of the Texas population—which is the same percentage as Latinos in deep-blue California -- while African Americans make up 12.5% of the population.

Angle sees signs of hope for Democrats in those figures. He notes that Texas' Latino population has grown at 10 times the rate of the Anglo population, and the African American population is growing at five times as fast.

Hispanic non-voters in Texas tend to be younger and more liberal -- a potential trove of Democratic votes. But whether they turn out in force to oppose Trump remains to be seen, particularly when the most likely scenario is that Texas will stay in the Republican column.

John Kelly, a 68-year-old retired civil engineer who lives in the outskirts of San Antonio, said with Clinton and Trump at the top of the ticket, he is horrified by his choices.

He said he probably will reluctantly vote for Trump -- as well as Hurd in the congressional race. Kelly appreciates that Hurd is a "reasonable, rational Republican" who has kept the presidential nominee "at arms-length."

Trump's "brash comments have generally been pretty appalling," Kelly said. "He seems not well-informed on a lot of topics that a presidential candidate should be informed about --- too numerous to mention. There are a lot of issues that he has tended to shoot from the hip, rather than think through and understand the details."

Kelly said his best hope is that Trump will be willing to listen to his advisers.

"I've voted in every election since I was old enough to vote, and these are absolutely the worst choices we've ever had, for sure."