DALLAS – In the political heart of Texas, a state Republicans have dominated for decades, Democrats say they are gaining ground – and one of the reasons rode into Dallas-Fort Worth on Thursday.

His name: Donald Trump.

While Trump's policies on immigration, trade and the economy remain popular in Republican-leaning Texas, Democrats say the president's actions are helping them build a base of their own among Hispanics, city dwellers and college-education professionals in the Lone Star State.

"Texas Democrats are rising," Dallas County Judge Clay Jenkins said as Trump supporters gathered for a rally at a sports arena in downtown Dallas. He added, "once Texas turns blue, the White House will follow for a long time."

At the rally later in the evening, Trump scoffed at the notion that the Lone Star State is somehow in play, telling supporters: "Donald Trump is not going to lose Texas, I can tell you that."

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Indeed, the president is still favored to carry Texas in the 2020 election – he won it by nine percentage points in 2016. But members of both parties said Democrats are in a position to make it more of a challenge.

And while Texas Democrats haven't won a statewide race since 1994, they nearly captured a Senate seat last year and are closing the gap in legislative and congressional elections.

"It's fair to say the state is more competitive than it has been, and the threat is real," said Texas-based Republican political consultant Matt Mackowiak, though he added: "I do not think it will be in play in the presidential race."

Trump supporters could not be more confident about Texas, noting that the state has seen increases in job creation and energy production since Trump took office, while Democrats are promoting "socialist" ideas on health care and gun control.

"There are too many people who feel the way I do" in Texas, said Brenda Lewis, 72, a Fort Worth retiree who grabbed a front-row seat at the rally. "They don't want to change it to Cuba."

Trump didn't visit Texas on Thursday because he's worried about losing the state, aides said. From Texarkana to El Paso, the state is a giant ATM for presidential candidates in both parties, and Trump began his day by raising an estimated $5.5 million at fundraisers in Fort Worth.

Trump then headed to nearby Johnson County to help cut the ribbon at a new Louis Vuitton leather manufacturing workshop, an appearance in which he highlighted plans to make jobs a major campaign issue.

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As he did at rallies last week in Minnesota and Louisiana, Trump used his Texas gig to buck up his base as he faces numerous challenges back in Washington, D.C. – most notably an impeachment inquiry led by House Democrats.

Trump and his Texas supporters predicted that a backlash against impeachment will help Trump.

"People like us will come out in force," said Sandra Brewer, 52, a flight attendant from Granbury, Tex.

Standing outside American Airlines Center hours before the rally, Brewer added that "President Trump goes through so much day after day. Most people would have been crushed by now. But he keeps going and going."

Democrats dream of a Blue Texas

Democrats and some political scientists have talked about it for years: An emerging "Blue Texas," the color that television news networks use to identify states that go Democratic in presidential elections.

Proponents cite major demographic shifts in one of the nation's fastest growing states. Much of that growth is in Hispanic communities and the big city areas of Dallas, Houston, Austin and San Antonio; Democrats said many of these new Texas residents are voting with them.

"All of our new voters are going Democratic by a ratio of 5-to-1," said Ed Espinoza, executive director of a political organization called Progress Texas.

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Trump is a trigger for many of these voters, according to state Democrats. His efforts to crack down on immigration are alienating Hispanic voters; his aggressive style, including attacks on allies and lawmakers of color, turn off many suburbanites, particularly women.

"Trump is a huge liability for the Republican Party," said Brittany Switzer, a spokesperson for the Texas Democratic Party. One result, she said, is "we see a huge coalition and we're looking to build that coalition."

Republicans said the demographic argument is overstated. There are many conservative Hispanic people, they said, and GOP candidates in Texas can get a fair share of their votes; same with the growing suburbs.

Still, there is Republican concern that manifested itself in a high-profile Senate race just last year.

Dallas looked pretty red on Thursday

Supporters from around Texas, along with throngs of street vendors from all over the country who hop from Trump rally to Trump rally, began arriving at the 20,000-seat American Airlines Center around daybreak. By noon, the lines with a dozen or more people standing abreast filled about four city blocks north of downtown.

The crowd at the arena's northeast side was entertained by a talk show-style political program produced by the Trump campaign. A live band that covered such singles as Merle Haggard's "Mama Tried," Pink Floyd's "The Wall" and "The Joker" by the Steve Miller Band kept the burgeoning crowd entertained.

During the performance of "The Wall," the line stating "we don't need no thought control" was changed to "we don't need no gun control."

Franklin Hughes, a vendor from South Carolina attending his 30th rally, said business was steady despite the competition. The talk of impeachment in the nation's capital has done nothing but improve sales, he said.

"It isn't hurting my business one bit," Franklin said. "It's making it better."

Ballad of Beto O'Rourke and Ted Cruz

O'Rourke, a former House member, did not defeat the first-term incumbent Sen. Ted Cruz – but he came as close to winning as any Texas-wide Democratic candidate has in a quarter-century.

While Cruz won 50.9% to 48.3%, some analysts said the race foreshadowed the emerging and more politically competitive Texas. O'Rourke raised around $80 million and activated hundreds of thousands of new voters, particularly in the growing urban areas.

O'Rourke certainly sees it as a sign of the future. In seeking the Democratic presidential nomination, he claims he could carry Texas and its 38 electoral votes, foreclosing Trump's hopes to victory nationwide.

After Trump announced his rally in Dallas, O'Rourke scheduled a counter-rally Thursday evening in nearby Grand Prairie. He called it a "rally against fear."

Cruz also sees a changing Texas. In September, he told a group of reporters that suburban voters, particularly women, are "moving left," and "that’s turning states with big suburban populations – states like Texas, states like Georgia, states like Arizona – much more purple.”

Referring to fellow Republicans, Cruz said: "If we lose Texas, it’s game over.”

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Whither Republican Texas?

Texas Republicans say they don't see a Democratic state anytime soon. Some called 2018 an anomaly, in part because Cruz was relatively unpopular among other Republicans. GOP members noted that the incumbent governor, Greg Abbott, won his reelection easily.

O'Rourke's fundraising would be hard for a presidential candidate to duplicate, they said. It's questionable as to whether the Democrats would be willing to spend that kind of money on a presidential race in Texas, and might to want to spread it to more competitive states.

Said Mackowiak: "2018 was a very weird year in Texas."

As for 2020, Texas Republicans noted that Trump did win by 9 percentage points in 2016, and a reversal of that size is hard to imagine.

Steve Munisteri, a former GOP state chairman in Texas, said it all boils down to numbers.

Generally, in recent elections, statewide Republican candidates get around 4.5 million votes, he said; Democrat candidates have a base of around 4 million.

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Given the state's growth, Munisteri's new target is 5.5 million voters. And, as usual, it will boil down to whichever party can turn out that many votes.

"If the Republicans don't get out their vote, and the Democrats do turn out their vote, the Democrats can win a statewide race," he said.

It doesn't look like the Alamo for either party; Munisteri said getting out all those new voters in future elections is more like another battle.

"It's going to be like the western front in World War I," Munisteri said. "Trench warfare."

At the rally in Dallas, Trump backers predicted an easy win next year, though some were less certain about the future. They acknowledged that Democrats are coming on in the state.

"Maybe in 2024, later on down the line," said Heather Box, 43, a "lifelong Texan" and "lifelong Republican" who lives in Addison, Texas, near Dallas. "I just don't think it's going to happen now. There's just not enough of them yet."

Contributing: John C Moritz Austin Bureau USA TODAY NETWORK, Corpus Christi Caller-Times