WASHINGTON - President Donald Trump's marquee campaign promise to build a border wall is getting a tepid push in Congress, but it did not always have the support of the two Texans currently being considered to be his next Homeland Security secretary.

Former Gov. Rick Perry, Trump's energy secretary, said in 2011 that a 2,000-mile fence "doesn't make sense."

Congressman Michael McCaul, in a 2015 interview, called it "kind of simplistic."

Like a lot of Texas Republicans, Perry and McCaul have long advocated for beefing up the border in other ways, and have only recently in their careers come to embrace Trump's vision of a wall.

It is their more holistic approach - and not Trump's - that took form Thursday in a $15 billion border security bill introduced by U.S. Sen. John Cornyn that would add layers of infrastructure, technology and "boots on the ground" on the Mexican border.

"Infrastructure, wall systems, are an important piece of the story," Cornyn said. "But they're not the whole story."

McCaul made the same point last week when he rolled out the House version of the border bill, a similar, $15 billion plan. "We must have physical barriers - including a wall, where necessary," said McCaul, chairman of the House Homeland Security Committee.

But McCaul's emphasis on technology and law enforcement - mirroring Perry's policies as governor - does not match Trump's vision for a 2,000-mile border wall paid for by Mexico.

The two Texans also have run afoul of border and immigration hawks in other ways. Positions they have taken on foreign worker visas and legal migrant labor - issues important to Texas farmers - have earned them low grades from NumbersUSA, a group that supports Trump's "America First" policies and advocates for reductions in all forms of immigration.

"Neither one of them has shown a real consciousness that immigration policy is not just about security, but heavily about how it influences the labor market," said Roy Beck, founder and president of NumbersUSA. "It's not just about physical security. It's about economic security."

A political symbol

The next Homeland Security secretary will be taking over an immigration system that is under fire from all sides.

In Texas, produce farmers like Bernie Phiel, 66, of Lubbock, are watching nervously as Mexican farmworkers granted amnesty by the U.S. government during the 1980s are getting to an age where they will soon be retiring. Farmers are hoping Congress will pass legislation allowing easier access for temporary farm workers from Mexico, but with the heated politics around immigration passing such a bill would likely be an uphill climb.

"There's no one to take their place," Phiel said of the retiring workers. "People need to wake up. We have a severe, severe labor shortage in the vegetable fields."

But it's the fraught politics of the wall that will likely occupy the new Homeland Security Secretary when Congress returns in September to iron out spending bills for the next year, including a recent House-passed measure allocating $1.6 billion for Trump's wall.

Even as the Trump administration has begun to acknowledge that a $20 billion-plus border-length wall will never become a reality, there are signs that Trump has been saddled by its significance as a political symbol.

Trump reportedly described the wall as "the least important thing we are talking about, but politically this might be the most important." That is according to a transcript obtained by the Washington Post and released Thursday of a call between Trump and Mexican President Enrique Peña Nieto last January. Trump appeared to be pressing the Mexican government privately to end its public defiance on paying for the wall.

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While their positions on the wall have not always aligned with Trump, both Perry and McCaul have been vetted by the administration already.

McCaul was considered for the Homeland Security post last fall, before losing out to former Marine Corps Gen. John Kelly, who took over this week as White House chief of staff.

Perry has already gone through the Senate confirmation process as Trump's pick to head the Energy Department. His selection, however, would create another cabinet opening for the Trump administration.

But for both Perry and McCaul, it's been a long journey to meet Trump on the issue of the border.

Perry had to make amends with Trump since their days as rivals in the Republican presidential primaries, when Trump attacked him in a tweet for "an absolutely horrible job of securing the border." He declared then that the Texan should be "ashamed of himself."

Asked about Trump's attacks during the summer of 2015, Perry said in a television interview: "Well, I don't think he understands the challenge, obviously. I was the governor of Texas for 14 years. The governor of that state with the 1,200-mile Mexican border."

Despite Perry's record as a border state governor, the issue dogged him in the 2012 presidential campaign as well. He was bludgeoned by opponents as "soft on illegal immigration." In one exchange with candidate Rick Santorum, of Pennsylvania, Perry even questioned the logic of building a wall on the U.S. Mexico border.

"The idea that you are going to build a wall, a fence for 1,200 miles, and then go 800 miles more to Tijuana, does not make sense. You put the boots on the ground," Perry said.

Perry's first presidential campaign eventually collapsed after he accused his Republican opponents of not having a "heart" about immigrants.

Raised on a cotton farm outside Abilene, Perry long maintained the more relaxed attitudes toward illegal immigration commonplace among the Texas farmers, who rely on migrant workers to get their crops to market.

During his first year as governor, Perry helped advance legislation that let children in the country illegally pay in-state tuition for college, a policy called the Texas DREAM Act, for which he received much conservative blowback.

But after dropping out of the 2012 presidential race, Perry returned to Austin with a new plan.

He ordered officers with the Texas Department of Public Safety to begin cracking down on immigrants. Soon officers began setting up checkpoints along the roads and even stopping people walking along the sidewalks to check their immigration status, said John Michael Torres, a spokesman for the South Texas immigrant advocacy group La Union del Pueblo Entero.

"DPS went from a law enforcement agency patrolling, giving out tickets to the face of immigration enforcement," he said. "Perry did have that compassionate approach [earlier in his career] but there was a certain point he saw an opportunity to shift his image, especially after his 2012 GOP campaign."

Hard-liners not convinced

McCaul has more recently come into alignment with Trump on the wall.

In a 2015 television interview, he called it "kind of simplistic" and a "knee jerk response." But in a Fox News op-ed after Trump's election, he vowed to "stand side-by-side" with Trump on immigration and, notably, the wall. "We are going to build the wall," he wrote. "Period."

Despite the turnaround, McCaul has yet to convince some hard-liners.

Mark Krikorian, executive director of the conservative Center for Immigration Studies, wrote in a tweet: "House Homeland Chairman McCaul was angling for the DHS job last time, but his reputation as 'No Wall McCaul' should be a deal-killer."

Whether it is remains to be seen. Having carved out an expertise in border security, immigration, and cyber-security as chairman of the Homeland Security Committee since 2013, McCaul brings a deep knowledge of the terrain.

Cornyn, who hired McCaul when he was Texas Attorney General, praised his qualifications Thursday, along with those of Perry.

"There are few people in America that know more about the border than our former governor of Texas," he said.

As for their past differences, Beck they are hardly unique to Washington. "Politics has plenty of room for people to make statements in the heat of a campaign that somehow or another get by it," he said. "If you band that kind of hypocrisy, you're going to have a lot of very short political careers."