It only took until 3pm on Monday to set a new first-day, early-voting record in El Paso County, Texas. By the end of the day, the 19,000-plus participants doubled the old record of 8,000.  

Sunshine Castro, who took part in early voting at an El Paso library, said, “I went in there and everybody was surprised that the line went all the way to the other side of the library. I haven’t seen it like that, ever.”

The surge in early-voting interest in Texas may be linked to how close the presidential race is there, compared with previous elections. Data from RealClearPolitics, which combined five Texas presidential polls, shows Hillary Clinton is trailing Donald Trump by just five points. To put that into context, Texas has not been won by a Democrat since Jimmy Carter beat Gerald Ford in 1976.

“I definitely think Texas is a battleground state. We’ve been working towards this for the past several election cycles,” said  Iliana Holguin, El Paso County Democrats chairwoman.

But Republicans in El Paso dispute the polls. They say they don't properly take all voters into account, especially first-time voters. They also believe many people are voting for Trump but won’t say so when asked by a pollster.

Bob Pena, with the El Paso County Republicans, said, “They call into this office, I haven’t voted in ten years, I don’t know if my voter registration is still good, or I’ve never voted. This is where much of the impact from the Trump campaign is coming from.”

At the state level, Texas has a Republican majority. The governor and other top elected officials are all Republican, along with all members of the Texas Supreme Court. There also is a Republican majority in the Texas State Legislature.

But El Paso is overwhelmingly Democratic. In fact, most Democrats running for state, county and local office in the area run unopposed. El Paso Democrats are trying to carry their local momentum statewide.

“The polls in Texas are as close as they’ve ever been,” Holquin said. “And so we are really working hard here in El Paso and the Democratic Party all across Texas to make sure that we get our voters out to vote. Because we really think it’s a possibility that this year, Texas is going to turn blue.”

But while Republicans admit the demographics are changing, they don’t see Texas turning blue any time soon - and especially during this election.

“You see twenty times more participation in a Trump rally then you see in a Hillary rally. That’s an important thing that should be measured but it’s not,” Pena said.   

In Texas, voters do not register for a political party when they register to vote. Instead, they become a member of a party when they participate in that party’s primary. In this year’s presidential primaries, Republicans had 20 percent voter turnout, while Democrats had 10 percent.

Ray Bogan is a Fox News multimedia reporter based in El Paso, Texas. Follow him on twitter: @RayBogan