In a hulking East Austin building without a window or air conditioning, several hundred sweat-drenched but happy Travis County Democrats gathered Tuesday to cheer U.S. Sen. Tim Kaine of Virginia, their party’s nominee for vice president, and revel in their buoyant sense that this year just might be a little bit different.

"This team, we’re serious about Texas, because we know the kind of work you can do," said Kaine, standing alongside a big blue map of Texas with Hillary Clinton’s logo at its heart. "We’re going to go after Texas."

"The way we will win is because of what you’re doing right now," Kaine told the volunteers, seated on plastic folding chairs in front of folding tables at the Travis County Democrats’ coordinated campaign office where they escape the summer heat for more sweltering confines to make phone calls on behalf of the party ticket, from top to bottom.

READ: Herman: Can Trump deliver Texas for Democrats?

Matthew Dowd, an Austinite who was chief strategist for George W. Bush’s 2004 presidential campaign, tweeted some cold water on Kaine’s optimism: "This is just silly. Only way Hillary carries Texas is if she is winning more than 15 points nationally."

Georgia Gov. Jimmy Carter in 1976 was the last Democratic presidential candidate to win Texas, and Democrats haven’t won any statewide office in Texas for more than two decades.

But if Texas Democrats, especially after a shellacking in the 2014 gubernatorial election, know there’s little to be gained by raising expectations, they also see the possibility that Donald Trump could lead the Republicans to a historic defeat that could put Texas in play and, at the very least, help their party pick up a handful of state House seats and a swing congressional district.

WATCH: U.S. Sen. Tim Kaine visits Chapala Restaurant on East Cesar Chavez Street in Austin

"Let me tell you, the work that you’re doing and the fact that Sen. Kaine is here, the Democratic candidate for vice president is here today, is going to make a difference in races all across this state," state Sen. Kirk Watson, who has known Kaine since Watson was mayor of Austin and Kaine was mayor of Richmond.

State Rep. Richard Raymond of Laredo, a longtime Clinton supporter and the political director for the presidential campaign in Texas, said that while he isn’t making any predictions for the final outcome, he expects the Clinton-Kaine ticket to do better than any Democratic nominees in a very long time, in part because of the identity of their Republican rival.

"We should be scared of Trump," said Raymond, adding that fear of Trump will drive women in larger numbers to vote for Clinton and Hispanics to turn out in record numbers.

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Trump has had a rough 10 days since the end of the July party conventions, with Clinton opening up a comfortable lead of nearly 8 points in the Real Clear Politics polling average.

At a rally Tuesday in Wilmington, N.C., Trump warned that if Clinton were elected and got to select the decisive Supreme Court justice on whom a gun rights case would pivot, it would be "a horrible day."

"If she gets to pick her judges, nothing you can do, folks," Trump said, "Although the Second Amendment people — maybe there is, I don’t know."

"I saw it reported, and when I read the quote, I really frankly couldn’t believe he said it," Kaine told reporters about Trump’s comments after rallying the Democratic volunteers. "So I went to watch the video of it and found that he had said it exactly the way it was printed."

"Nobody who is seeking a leadership position, especially the presidency, the leadership of the country, should do anything to countenance violence, and that’s what he was saying. There is a beautiful phrase in the Gospel of Luke that says, ‘From the fullness of the heart, the mouth speaks,’" Kaine said. "What comes out often reveals something really important about who you are, and I think Donald Trump revealed again … a complete temperamental misfit with the character that’s required to do the job."

"We’ve got to be pulling together and countenancing violence is not something any leader should do," Kaine said.

After speaking to the Democratic activists, Kaine stopped at Chapala Restaurant on East Cesar Chavez Street, speaking in Spanish with patrons and the restaurant staff, before heading to an Austin fundraiser.

At Chapala, Kaine spoke with a Spanish-speaking customer who said he had lived here for 15 years, had never been in trouble with the law but didn’t have papers. Kaine told the man that, "in my first months in the Senate, I gave a speech in Spanish on the need for immigration reform. Hillary and I are supporters of immigration reform and Trump isn’t."

"They say Mexicans sell drugs and this and that, kick those people out … they are not good," the diner replied. "My people work."

"We understand that the Latino community is a community of faith, family and work," Kaine said. "They are a source of strength for our country."

Kaine is scheduled to attend fundraisers Wednesday in Fort Worth and Dallas.